Add a help section about preferences set by Vimperator at startup.

common/content/buffer.js

@@ -207,7 +207,8 @@ function Buffer() //{{{
         "Start caret mode",
         function ()
         {
-            // setting this option triggers an observer which takes care of the mode setting
+            // setting this option notifies an observer which takes care of the
+            // mode setting
             options.setPref("accessibility.browsewithcaret", true);
         });
 

vimperator/locale/en-US/index.txt

@@ -207,7 +207,7 @@ section:Ex{nbsp}commands[ex-cmd-index,:index]
 ||:pageinfo|| Show various page information +
 ||:pagestyle|| Select the author style sheet to apply +
 ||:play|| Replay a recorded macro +
-||:preferences|| Show Firefox preferences +
+||:preferences|| Show Firefox preferences dialog +
 ||:pwd|| Print the current directory name +
 ||:qmark|| Mark a URL with a letter for quick access +
 ||:qmarks|| Show all QuickMarks +

vimperator/locale/en-US/options.txt

@@ -162,21 +162,18 @@ Environment variables are expanded for path options like 'cdpath' and
 'runtimepath'. The variable notation is _$VAR_ (terminated by a non-word
 character) or _$\\{VAR}_. _%VAR%_ is also supported on Windows.
 
-section:Setting{nbsp}Firefox{nbsp}options[firefox-options]
+section:Setting{nbsp}Firefox{nbsp}options[firefox-options,preferences]
 
-Most Firefox options are not touched/overridden by Vimperator. In order to set
+Firefox options can be viewed and set with the following commands:
-any of these preferences use either of the following:
 
 |:prefs| |:preferences|
 ||:pref[erences]||
 ________________________________________________________________________________
-Show Browser Preferences +
+Show the Firefox preferences dialog. You can change the browser preferences
-You can change the browser preferences from this dialog. Be aware that not
+from this dialog. Be aware that not all Firefox preferences work, because
-all Firefox preferences work, because Vimperator overrides some key
+Vimperator overrides some key bindings and changes Firefox's GUI.
-bindings and changes Firefox's GUI.
 ________________________________________________________________________________
 
-
 |:prefs!| |:preferences!|
 ||:pref[erences]!||
 ________________________________________________________________________________
@@ -184,7 +181,6 @@ Opens about:config in the current tab where you can change advanced Firefox
 preferences.
 ________________________________________________________________________________
 
-
 |:set!| |:set-!|
 ||:se[t]! {preference}={value}|| +
 ________________________________________________________________________________
@@ -192,6 +188,19 @@ Change any Firefox {preference} (those in the about:config window). You can also
 reset/delete those preferences with [c]:set! {preference}&[c].
 ________________________________________________________________________________
 
+|overridden-preferences| +
+
+Vimperator sets several Firefox preferences at startup. If this is undesirable,
+they can be changed to a different value in your RC file using
+[c]:set! {preference}={value}[c]
+
+The following preferences are set:
+
+* browser.startup.page
+* dom.popup_allowed_events
+
+// TODO: others?
+
 section:List{nbsp}of{nbsp}options[list-options]
 
 |\'act'| |\'activate'|