Update installation docs

De-emphasize Vimball as an installation method (I consider it a broken
format, not just because of the way it gloms all plug-ins into a single
shared namespace, but because it frequently fails to extract correctly,
leading to support tickets). I'd like to eventually even stop
distributing the Vimball at all, but the first gentle step is not
documenting Vimball's existence.

Add info about some of the more popular plug-in managers. Pathogen is
still king of simplicity and robustness, but the allure of shiny,
overengineered things and the widespread misunderstanding of Git
submodules has caused the marketplace to fragment. Oh well.

doc/command-t.txt

@@ -5,7 +5,6 @@ CONTENTS                                        *command-t-contents*
  1. Introduction            |command-t-intro|
  2. Requirements            |command-t-requirements|
  3. Installation            |command-t-installation|
- 3. Managing using Pathogen |command-t-pathogen|
  4. Trouble-shooting        |command-t-trouble-shooting|
  5. Usage                   |command-t-usage|
  6. Commands                |command-t-commands|
@@ -144,26 +143,128 @@ folder.
 
 INSTALLATION                                    *command-t-installation*
 
-You can install Command-T by obtaining the source files and building the C
-extension. The recommended way to get the source is by using a plug-in
-management system such as Pathogen (see |command-t-pathogen|).
+You install Command-T by obtaining the source files and building the C
+extension.
+
+The recommended way to get the source is by using a plug-in management system.
+There are several such systems available, and my preferred one is Pathogen
+(https://github.com/tpope/vim-pathogen) due to its simplicity and robustness.
+
+Other plug-in managers include:
+
+- Vundle: https://github.com/gmarik/Vundle.vim (see |command-t-vundle|)
+- NeoBundle: https://github.com/Shougo/neobundle.vim (see
+  |command-t-neobundle|)
+- VAM: https://github.com/MarcWeber/vim-addon-manager (see |command-t-vam|)
+
+The following sections outline how to use each of these managers to download
+Command-T, and finally |command-t-compile| describes how to compile it.
+
+                                                         *command-t-pathogen*
+Obtaining the source using Pathogen ~
+
+Pathogen is a plugin that allows you to maintain plugin installations in
+separate, isolated subdirectories under the "bundle" directory in your
+|'runtimepath'|. The following examples assume that you already have
+Pathogen installed and configured, and that you are installing into
+`~/.vim/bundle`.
+
+If you manage your entire `~/.vim` folder using Git then you can add the
+Command-T repository as a submodule:
+
+  cd ~/.vim
+  git submodule add git://git.wincent.com/command-t.git bundle/command-t
+  git submodule init
+
+Or if you just wish to do a simple clone instead of using submodules:
+
+  cd ~/.vim
+  git clone git://git.wincent.com/command-t.git bundle/command-t
+
+Once you have a local copy of the repository you can update it at any time
+with:
+
+  cd ~/.vim/bundle/command-t
+  git pull
+
+Or you can switch to a specific release with:
+
+  cd ~/.vim/bundle/command-t
+  git checkout 1.10
+
+To generate the help tags under Pathogen it is necessary to do so explicitly
+from inside Vim:
+
+  :call pathogen#helptags()
+
+For more information about Pathogen, see:
+
+  https://github.com/tpope/vim-pathogen
+
+                                                           *command-t-vundle*
+Obtaining the source using Vundle ~
+
+Anywhere between the calls to `vundle#begin` and `vundle#end` in your
+`~/.vimrc`, add a `Plugin` directive telling Vundle of your desire to use
+Command-T:
+
+  call vundle#begin()
+  Plugin 'wincent/command-t'
+  call vundle#end()
+
+To actually install the plug-in run `:PluginInstall` from inside Vim. After
+this, you can proceed to compile Command-T (see |command-t-compile|).
+
+For more information about Vundle, see:
+
+  https://github.com/gmarik/Vundle.vim
+
+                                                        *command-t-neobundle*
+Obtaining the source using NeoBundle ~
+
+Anywhere between the calls to `neobundle#begin` and `neobundle#end` in your
+`~/.vimrc`, add a `NeoBundle` directive telling NeoBundle of your desire to use
+Command-T:
 
-Command-T is also distributed as a "vimball" which means that it can be
-installed by opening it in Vim and then sourcing it:
+  call neobundle#begin(expand('~/.vim/bundle/'))
+  NeoBundle 'wincent/command-t'
+  call neobundle#end()
 
-  :e command-t.vba
-  :so %
+To actually install the plug-in run `:NeoBundleInstall` from inside Vim. After
+this, you can proceed to compile Command-T (see |command-t-compile|).
 
-The files will be installed in your |'runtimepath'|. To check where this is
-you can issue:
+For more information about NeoBundle, see:
 
-  :echo &rtp
+  https://github.com/Shougo/neobundle.vim
+                                                              *command-t-vam*
+Obtaining the source using VAM ~
 
-The C extension must then be built, which can be done from the shell. If you
-use a typical |'runtimepath'| then the files were installed inside ~/.vim and
-you can build the extension with:
+After the call to `vam#ActivateAddons` in your `~/.vimrc`, add Command-T to
+the `VAMActivate` call:
 
-  cd ~/.vim/ruby/command-t
+  call vam#ActivateAddons([])
+  VAMActivate github:wincent/command-t
+
+After VAM has downloaded Command-T, you can proceed to compile it (see
+|command-t-compile|).
+
+For more information about VAM, see:
+
+  https://github.com/MarcWeber/vim-addon-manager
+
+                                                         *command-t-compile*
+Compiling Command-T ~
+
+The C extension must be built, which can be done from the shell. If you use a
+typical Pathogen, Vundle or NeoBundle set-up then the files were installed inside
+`~/.vim/bundle/command-t`. A typical VAM installation path might be
+`~/.vim/vim-addons/command-t`.
+
+Wherever the Command-T files were installed, you can build the extension by
+changing to the `ruby/command-t` subdirectory and running a couple of commands
+as follows:
+
+  cd ~/.vim/bundle/command-t/ruby/command-t
   ruby extconf.rb
   make
 
@@ -179,7 +280,7 @@ Note: If you are on OS X Mavericks and compiling against MacVim, the default
 system Ruby is 2.0 but MacVim still links against the older 1.8.7 Ruby that is
 also bundled with the system; in this case the build command becomes:
 
-  cd ~/.vim/ruby/command-t
+  cd ~/.vim/bundle/command-t/ruby/command-t
   /System/Library/Frameworks/Ruby.framework/Versions/1.8/usr/bin/ruby extconf.rb
   make
 
@@ -202,50 +303,6 @@ repository with:
 
   su -c 'yum install vim-command-t'
 
-MANAGING USING PATHOGEN                         *command-t-pathogen*
-
-Pathogen is a plugin that allows you to maintain plugin installations in
-separate, isolated subdirectories under the "bundle" directory in your
-|'runtimepath'|. The following examples assume that you already have
-Pathogen installed and configured, and that you are installing into
-~/.vim/bundle. For more information about Pathogen, see:
-
-  http://www.vim.org/scripts/script.php?script_id=2332
-
-If you manage your entire ~/.vim folder using Git then you can add the
-Command-T repository as a submodule:
-
-  cd ~/.vim
-  git submodule add git://git.wincent.com/command-t.git bundle/command-t
-  git submodule init
-
-Or if you just wish to do a simple clone instead of using submodules:
-
-  cd ~/.vim
-  git clone git://git.wincent.com/command-t.git bundle/command-t
-
-Once you have a local copy of the repository you can update it at any time
-with:
-
-  cd ~/.vim/bundle/command-t
-  git pull
-
-Or you can switch to a specific release with:
-
-  cd ~/.vim/bundle/command-t
-  git checkout 0.8b
-
-After installing or updating you must build the extension:
-
-  cd ~/.vim/bundle/command-t/ruby/command-t
-  ruby extconf.rb
-  make
-
-While the Vimball installation automatically generates the help tags, under
-Pathogen it is necessary to do so explicitly from inside Vim:
-
-  :call pathogen#helptags()
-
 
 TROUBLE-SHOOTING                                *command-t-trouble-shooting*
 
@@ -362,7 +419,7 @@ The following is also available on terminals which support it:
     <Esc>       cancel (dismisses file listing)
 
 Note that the default mappings can be overriden by setting options in your
-~/.vimrc file (see the OPTIONS section for a full list of available options).
+`~/.vimrc` file (see the OPTIONS section for a full list of available options).
 
 In addition, when the file listing has focus, typing a character will cause
 the selection to jump to the first path which begins with that character.
@@ -428,15 +485,15 @@ By default Command-T comes with only two mappings:
   <Leader>b     bring up the Command-T buffer window
 
 However, Command-T won't overwrite a pre-existing mapping so if you prefer
-to define different mappings use lines like these in your ~/.vimrc:
+to define different mappings use lines like these in your `~/.vimrc`:
 
   nnoremap <silent> <Leader>t :CommandT<CR>
   nnoremap <silent> <Leader>b :CommandTBuffer<CR>
 
 Replacing "<Leader>t" or "<Leader>b" with your mapping of choice.
 
 Note that in the case of MacVim you actually can map to Command-T (written
-as <D-t> in Vim) in your ~/.gvimrc file if you first unmap the existing menu
+as <D-t> in Vim) in your `~/.gvimrc` file if you first unmap the existing menu
 binding of Command-T to "New Tab":
 
   if has("gui_macvim")
@@ -452,8 +509,8 @@ overriding the mappings are listed below under OPTIONS.
 
 OPTIONS                                         *command-t-options*
 
-A number of options may be set in your ~/.vimrc to influence the behaviour of
-the plug-in. To set an option, you include a line like this in your ~/.vimrc:
+A number of options may be set in your `~/.vimrc` to influence the behaviour of
+the plug-in. To set an option, you include a line like this in your `~/.vimrc`:
 
     let g:CommandTMaxFiles=20000
 
@@ -570,7 +627,7 @@ Following is a list of all available options:
       |g:CommandTScanDotDirectories| affects the behaviour at scan-time.
 
       Note also that even with this setting off you can still use Command-T to
-      open files inside a "dot-directory" such as ~/.vim, but you have to use
+      open files inside a "dot-directory" such as `~/.vim`, but you have to use
       the |:cd| command to change into that directory first. For example:
 
         :cd ~/.vim
@@ -622,7 +679,7 @@ Following is a list of all available options:
 As well as the basic options listed above, there are a number of settings that
 can be used to override the default key mappings used by Command-T. For
 example, to set <C-x> as the mapping for cancelling (dismissing) the Command-T
-window, you would add the following to your ~/.vimrc:
+window, you would add the following to your `~/.vimrc`:
 
   let g:CommandTCancelMap='<C-x>'
 
@@ -762,7 +819,7 @@ Why doesn't the Escape key close the match listing in terminal Vim? ~
 
 In some terminals such as xterm the Escape key misbehaves, so Command-T
 doesn't set up a mapping for it. If you want to try using the escape key
-anyway, you can add something like the following to your ~/.vimrc file:
+anyway, you can add something like the following to your `~/.vimrc` file:
 
   if &term =~ "xterm" || &term =~ "screen"
     let g:CommandTCancelMap = ['<ESC>', '<C-c>']
@@ -940,10 +997,10 @@ per hour from the authoritative repository:
 Patches are welcome via the usual mechanisms (pull requests, email, posting to
 the project issue tracker etc).
 
-As many users choose to track Command-T using Pathogen, which often means
-running a version later than the last official release, the intention is that
-the "master" branch should be kept in a stable and reliable state as much as
-possible.
+As many users choose to track Command-T using Pathogen or similar, which often
+means running a version later than the last official release, the intention is
+that the "master" branch should be kept in a stable and reliable state as much
+as possible.
 
 Riskier changes are first cooked on the "next" branch for a period before
 being merged into master. You can track this branch if you're feeling wild and