Store jQuery.data for plain objects on objects

[john]

There's no reason to store the data in the jQuery.cache for plain objects as there aren't any memory leak issues associated with it. Instead we can attach the data directly to the objects themselves (allowing them to be garbage collected at a later time).

Discussion: ​http://forum.jquery.com/topic/data-object-and-memory-leak

[john]

Fixed. ​http://github.com/jquery/jquery/commit/a49e6b63131e292bc1c31ee98b300ba87ce99162