[clockPreferences] Fix translations

The preference dialog for the panel clock does not set its gettext
domain, so it's not translated even if though translations are
already available.
Fix by setting the domain in the GtkBuilder file and binding the
domain to the locale directory.

https://bugzilla.gnome.org/show_bug.cgi?id=618873

js/prefs/clockPreferences.js

@@ -7,6 +7,8 @@ const GConf = imports.gi.GConf;
 const Lang = imports.lang;
 const Signals = imports.signals;
 
+const Gettext = imports.gettext;
+
 const GCONF_DIR        = '/desktop/gnome/shell/clock';
 const FORMAT_KEY       = GCONF_DIR + '/format';
 const SHOW_DATE_KEY    = GCONF_DIR + '/show_date';
@@ -80,6 +82,9 @@ Signals.addSignalMethods(ClockPreferences.prototype);
 function main(params) {
     if ('progName' in params)
         GLib.set_prgname(params['progName']);
+    if ('localeDir' in params)
+        Gettext.bindtextdomain('gnome-shell', params['localeDir']);
+
     Gtk.init(null, null);
 
     let clockPrefs = new ClockPreferences(params['uiFile']);