Enhancing "closest" method for delegation

[mike.helgeson]

I propose adding a second argument to the "closest" method that will act as the end point for searching up the document tree. It can behave just like the "context" argument in the jQuery mother function. It will optimize the performance of a common pattern I have seen in my own code since the addition of this method. The new usage could be as follows:

$("table").bind("click",function( event ){

var $td = $( event.target ).closest("td", event.currentTarget );

});

Because I bound the handler to "table" I do not want to search any higher than that element for selector matches. Furthermore, if there was a selector match outside of the containing element, it could potentially and accidentally be matched.

I have attached the modified method. It is a very small change, and makes "closest" even more powerful for advanced developers.

[mike.helgeson]

duplicate ticket:  http://dev.jquery.com/ticket/4072