Add :extoptions command

vimperator/NEWS

@@ -15,7 +15,7 @@
       and <C-A> are equivalent, to map the uppercase character use <C-S-A>.
 
     * add extension related commands - :extadd, :extdelete, :extdisable,
-      :extenable, :extensions
+      :extenable, :extensions, :extoptions
     * add '-javascript' flag to :autocommand
     * add 'private' - enter private browsing mode, matching 'PrivateMode'
       autocommand

vimperator/locale/en-US/gui.txt

@@ -114,6 +114,15 @@ ________________________________________________________________________________
 List all installed extensions.
 ________________________________________________________________________________
 
+|:exto| |:extoptions| +
+|:extp| |:extpreferences| +
+||:exto[ptions][!] {extension}|| +
+||:extp[references][!] {extension}|| +
+________________________________________________________________________________
+Open the preferences dialog for an extension. If [!] is given, open a dialog,
+otherwise open a buffer. See also 'newtab'.
+________________________________________________________________________________
+
 section:Sidebar[sidebar]
 
 |:sbcl| |:sbclose| +

vimperator/locale/en-US/index.txt

@@ -186,6 +186,7 @@ section:Ex{nbsp}commands[ex-cmd-index,:index]
 ||[c]:extdelete[c]||
 ||[c]:extdisable[c]||
 ||[c]:extenable[c]||
+||[c]:extoptions[c]||
 ||[c]:extensions[c]|| List all installed extensions +
 ||[c]:exusage[c]|| List all Ex commands with a short description +
 ||[c]:finish[c]|| Stop sourcing a script file +

vimperator/locale/en-US/options.txt

@@ -566,6 +566,7 @@ The possible values:
 *all*        All commands
 *addons*     [c]:addo[ns][c] command
 *downloads*  [c]:downl[oads][c] command
+*extoptions* [c]:exto[ptions][c] command
 *help*       [c]:h[elp][c] command
 *javascript* [c]:javascript![c] or [c]:js![c] command
 *prefs*      [c]:pref[erences]![c] or [c]:prefs![c] command