MAJOR CHANGE to theming system:

* Less complex
* Themes are only loaded once. Users share avail themes[] objects
* Themes are applied to configuration _once_
* Users can switch themes in configuration
* Other related improvements

core/menu_stack.js

@@ -101,7 +101,7 @@ MenuStack.prototype.goto = function(name, options, cb) {
 		client		: self.client, 
 	};
 
-	if(options) {
+	if(_.isObject(options)) {
 		loadOpts.extraArgs = options.extraArgs;
 	}