title: Mouseup event on document is not fired after hovering over iframe
body: <p>I am trying to get a div splitter working to resize two divs when I drag the splitter.
  I am trying to do this with mousedown, mousemove and mouseup events.  It works like a charm until I add my youtube iframe.
  Once I hover over the iframe the mouseup event to <code>$(document)</code> is not fired, I'm guessing it is taken by the iframe.
  I have a working <a href="https://jsfiddle.net/kfa0ja34/13/" rel="nofollow">example in jsfiddle</a>.</p>
  
  <p>In the example the mouseup event is fired until your mouse moves over the iframe.</p>