Event: Empty namespaces should be uneventfully ignored

Thanks @hamishdickson for the report!

Closes gh-1769

src/event.js

@@ -15,7 +15,7 @@ var
 	rkeyEvent = /^key/,
 	rmouseEvent = /^(?:mouse|pointer|contextmenu)|click/,
 	rfocusMorph = /^(?:focusinfocus|focusoutblur)$/,
-	rtypenamespace = /^([^.]*)(?:\.(.+)|)$/;
+	rtypenamespace = /^([^.]*)(?:\.(.+)|)/;
 
 function returnTrue() {
 	return true;