Add an 'rt' command to the Run dialog to reload the theme

This should be useful for theme authors who want to quickly reload
the theme without restarting the whole shell.

Signed-off-by: Federico Mena Quintero <federico@gnome.org>

https://bugzilla.gnome.org/show_bug.cgi?id=630428

js/ui/runDialog.js

@@ -207,6 +207,11 @@ RunDialog.prototype = {
 
                                    'debugexit': Lang.bind(this, function() {
                                        Meta.exit(Meta.ExitCode.ERROR);
+                                   }),
+
+                                   // rt is short for "reload theme"
+                                   'rt': Lang.bind(this, function() {
+                                       Main.loadTheme();
                                    })
                                  };