jquery/jquery-ui — pull request #573 by stresler (2012-01-16 18:29:14+00:00)
Title: Allow _over fires on non-accepting droppables. 

Allows hover events to be fired on DOM elements that are NOT in the accept: SELECTOR list. This is useful for providing visual feedback in areas that you can't drop a draggable, and for firing functions on hover events, such as switching tabs when holding a draggable over an inactive tab.