Replace UI uses of 'folder' with 'directory'

There are still methods and variables with the word "folder" in the
name, but at least user-facing messages and warnings should use the
correct terminology.

Signed-off-by: Jack Nagel <jacknagel@gmail.com>

Library/Homebrew/build.rb

@@ -62,7 +62,7 @@ def install f
       if ARGV.flag? '--git'
         system "git init"
         system "git add -A"
-        puts "This folder is now a git repo. Make your changes and then use:"
+        puts "This directory is now a git repo. Make your changes and then use:"
         puts "  git diff | pbcopy"
         puts "to copy the diff to the clipboard."
       end

Library/Homebrew/cmd/doctor.rb

@@ -243,10 +243,10 @@ def __check_subdir_access base
   cant_read.sort!
   if cant_read.length > 0
     puts <<-EOS.undent
-    Some folders in #{target} aren't writable.
+    Some directories in #{target} aren't writable.
     This can happen if you "sudo make install" software that isn't managed
     by Homebrew. If a brew tries to add locale information to one of these
-    folders, then the install will fail during the link step.
+    directories, then the install will fail during the link step.
     You should probably `chown` them:
 
     EOS
@@ -283,25 +283,25 @@ def __check_folder_access base, msg
 
 def check_access_pkgconfig
   __check_folder_access 'lib/pkgconfig',
-  'If a brew tries to write a .pc file to this folder, the install will\n'+
+  'If a brew tries to write a .pc file to this directory, the install will\n'+
   'fail during the link step.'
 end
 
 def check_access_include
   __check_folder_access 'include',
-  'If a brew tries to write a header file to this folder, the install will\n'+
+  'If a brew tries to write a header file to this directory, the install will\n'+
   'fail during the link step.'
 end
 
 def check_access_etc
   __check_folder_access 'etc',
-  'If a brew tries to write a file to this folder, the install will\n'+
+  'If a brew tries to write a file to this directory, the install will\n'+
   'fail during the link step.'
 end
 
 def check_access_share
   __check_folder_access 'share',
-  'If a brew tries to write a file to this folder, the install will\n'+
+  'If a brew tries to write a file to this directory, the install will\n'+
   'fail during the link step.'
 end
 
@@ -331,7 +331,7 @@ def check_xcode_prefix
   return if prefix.nil?
   if prefix.to_s.match(' ')
     puts <<-EOS.undent
-      Xcode is installed to a folder with a space in the name.
+      Xcode is installed to a directory with a space in the name.
       This may cause some formulae, such as libiconv, to fail to build.
 
     EOS
@@ -501,13 +501,16 @@ def check_for_config_scripts
 
   unless config_scripts.empty?
     puts <<-EOS.undent
-      Some "config" scripts were found in your path, but not in system or Homebrew folders.
+      Some "config" scripts were found in your path, but not in system or
+      Homebrew directories.
 
-      `./configure` scripts often look for *-config scripts to determine if software packages
-      are installed, and what additional flags to use when compiling and linking.
+      `./configure` scripts often look for *-config scripts to determine if
+      software packages are installed, and what additional flags to use when
+      compiling and linking.
 
-      Having additional scripts in your path can confuse software installed via Homebrew if
-      the config script overrides a system or Homebrew provided script of the same name.
+      Having additional scripts in your path can confuse software installed via
+      Homebrew if the config script overrides a system or Homebrew provided
+      script of the same name.
 
     EOS
 
@@ -537,7 +540,7 @@ def check_for_symlinked_cellar
                       which resolves to: #{HOMEBREW_CELLAR.realpath}
 
       The recommended Homebrew installations are either:
-      (A) Have Cellar be a real folder inside of your HOMEBREW_PREFIX
+      (A) Have Cellar be a real directory inside of your HOMEBREW_PREFIX
       (B) Symlink "bin/brew" into your prefix, but don't symlink "Cellar".
 
       Older installations of Homebrew may have created a symlinked Cellar, but this can
@@ -566,15 +569,15 @@ def check_for_multiple_volumes
 
   unless where_cellar == where_temp
     puts <<-EOS.undent
-      Your Cellar & TEMP folders are on different volumes.
+      Your Cellar and TEMP directories are on different volumes.
 
       OS X won't move relative symlinks across volumes unless the target file
       already exists.
 
       Brews known to be affected by this are Git and Narwhal.
 
       You should set the "HOMEBREW_TEMP" environmental variable to a suitable
-      folder on the same volume as your Cellar.
+      directory on the same volume as your Cellar.
 
     EOS
   end
@@ -797,7 +800,7 @@ def check_for_enthought_python
     Enthought Python was found in your PATH.
 
     This can cause build problems, as this software installs its own
-    copies of iconv and libxml2 into folders that are picked up by
+    copies of iconv and libxml2 into directories that are picked up by
     other build systems.
 
   EOS

Library/Homebrew/formula_installer.rb

@@ -232,7 +232,7 @@ def check_PATH
   def check_manpages
     # Check for man pages that aren't in share/man
     if (f.prefix+'man').exist?
-      opoo 'A top-level "man" folder was found.'
+      opoo 'A top-level "man" directory was found.'
       puts "Homebrew requires that man pages live under share."
       puts 'This can often be fixed by passing "--mandir=#{man}" to configure.'
       @show_summary_heading = true
@@ -242,7 +242,7 @@ def check_manpages
   def check_infopages
     # Check for info pages that aren't in share/info
     if (f.prefix+'info').exist?
-      opoo 'A top-level "info" folder was found.'
+      opoo 'A top-level "info" directory was found.'
       puts "Homebrew suggests that info pages live under share."
       puts 'This can often be fixed by passing "--infodir=#{info}" to configure.'
       @show_summary_heading = true