jquery/jquery — pull request #1580 by dcherman (2014-05-15 16:28:11+00:00)
Title: Event: Extend the jQuery.Event prototype instead of paving over it

The original definition of the jQuery.Event prototype was paving over the
`constructor` property which was causing jQuery.isPlainObject to
improperly report that an instance of jQuery.Event was a plain object.

Fixes #15090