add Ox..toggleClass() method

source/Ox/js/DOM.js

@@ -251,6 +251,16 @@ Ox.$ = Ox.element = function(value) {
             return this.css({display: 'block'});
         },
         /*@
+        toggleClass <f> Toggles a class name
+            (className) -> <o> This element
+            className <s> Class name
+        @*/
+        toggleClass: function(string) {
+            return this[
+                this.hasClass(string) ? 'removeClass' : 'addClass'
+            ](string);
+        },
+        /*@
         trigger <f> Triggers an event
             (event) -> <o> This element
         @*/