A large refactor of the event handling logic. Data and namespace information...

A large refactor of the event handling logic. Data and namespace information is maintained in a separate object now, no longer on the event handler. Proxy functions are no longer needed, as a result. Additionally execution order of the handlers is maintained, fixing #4261, and the execution of handlers is maintained even while they're being removed. Live events will be refactored separately.

test/unit/event.js

@@ -88,8 +88,9 @@ test("bind(), namespace with special add", function() {
 		},
 		setup: function(){},
 		teardown: function(){},
-		add: function( handler, data, namespaces ) {
-			return function(e) {
+		add: function( handleObj ) {
+			var handler = handleObj.handler;
+			handleObj.handler = function(e) {
 				e.xyz = ++i;
 				handler.apply( this, arguments );
 			};