jquery/jquery-ui — pull request #1250 by david04 (2014-05-16 11:51:55+00:00)
Title: Sortable: Adds an option to compare z-index of overlapping lists.

Adds an option (compareZIndex) to compare z-index of overlapping lists.

Addresses:
http://stackoverflow.com/questions/4092817/dealing-with-overlapping-jquery-sortable-lists
http://bugs.jqueryui.com/ticket/3452 (just for sortable)