Event binding should accept function returning Bool

[GoogleCodeExporter]

For a event listener function, returning false can cancel the event. This is 
useful feature for handling form submission/link clicking etc.

See http://www.w3schools.com/js/js_events.asp

So, the methods, like ClickCall, should be change to something like 
"ClickCall<T>(fn: T->Bool): JQuery". Or event simpler, "ClickCall(fn: Dynamic-
>Dynamic): JQuery".

Original issue reported on code.google.com by Andy.onthewings on 23 Mar 2010 at 9:28