add update-gitweb-daemon-from-options to docs

also deprecate (in documentation) this:

    config foo.bar =

i.e., allow only

    config foo.bar = ""

The sugar parser for the 'option' line can't deal with it and I decided
it's better to de-emphasise it.

See d8df4a9 (in the gitolite repo) for additional background/history.

git-config.mkd

@@ -13,26 +13,25 @@ Here's all you want to know about setting repo-specific git-config values.
 
 The syntax is simple:
 
-    config sectionname.keyname = [optional value_string]
+    config sectionname.keyname = value
 
 For example:
 
     repo gitolite
         config hooks.mailinglist = gitolite-commits@example.tld
         config hooks.emailprefix = "[gitolite] "
         config foo.bar = ""
-        config foo.baz =
 
 This does either a plain "git config section.key value" (for the first 2
-examples above) or "git config --unset-all section.key" (for the last 2
-examples).  Other forms of the `git config` command (`--add`, the
+examples above) or "git config --unset-all section.key" (for the last
+example).  Other forms of the `git config` command (`--add`, the
 `value_regex`, etc) are not supported.
 
 >   ----
 
 >   **WARNING**: simply deleting the config line from the `conf/gitolite.conf`
 >   file will *not* delete the variable from `repo.git/config`.  You have to
->   use the syntax in either of the last 2 examples to make gitolite execute a
+>   use the syntax in the last example to make gitolite execute a
 >   `--unset-all` operation on the given key.
 
 >   ----
@@ -45,7 +44,7 @@ available to [wild][] repos.
         config hooks.mailinglist = %GL_REPO-commits@example.tld
         config hooks.emailprefix = "[%GL_REPO] "
 
-You can repeat the 'config' line as many times as you like, and the last
+You can repeat the 'config' line as many times as you like, and the *last*
 occurrence will be the one in effect.  This allows you to override settings
 just for one project, as in this example:
 
@@ -60,8 +59,8 @@ just for one project, as in this example:
 The "delete config variable" syntax can also be used, if you wish:
 
     repo secret     # no emails for this one please
-        config hooks.mailinglist =
-        config hooks.emailprefix =
+        config hooks.mailinglist = ""
+        config hooks.emailprefix = ""
 
 As you can see, the general idea is to place the most generic ones (`repo
 @all`, or repo patterns like `repo foo.*`) first, and place more specific ones

options.mkd

@@ -3,6 +3,10 @@
 Some gitolite features are enabled, or gitolite's behaviour changed, by
 setting "options".
 
+A line like 'option foo = 1' is really just syntactic sugar for 'config
+gitolite-options.foo = 1', so everything in the [git-config][] page also
+applies here.
+
 Options are set by repo.  The syntax is very simple:
 
     option  foo.bar     =   baz
@@ -18,3 +22,19 @@ Here are the currently recognised options:
 
   * [mirroring][] related options -- tell gitolite who is the master server,
     and who are the slaves, for each repo.
+
+  * the optional post-compile trigger 'update-gitweb-daemon-from-options'
+    allows you to use options instead of special usernames gitweb and daemon
+    to determine access for those tools.
+
+Here's how to disable an option from a single repo if it was enabled earlier
+in a group (which you might guess from reading the [git-config][] page):
+
+    @g = r1 r2 r3
+
+    repo @g
+        option gitweb = 1
+
+    # but repo r2 should not be accessible by gitweb
+    repo r2
+        option gitweb = ""