Partially working with IE

Hi These changes incorporate the eventsource polyfill from yaffle to make dashing almost work on IE. Creating a new dashing dashboard with this branch shows the chart part of the convergence widget working on IE (and nothing broken on other browsers).  This proves the jobs send event data is being picked  up by the eventsource in IE.  But none of the batman bindings seem to work so the other widgets don't work.  There are no errors logged to the js console in IE and it's not immediately obvious to me how to debug this problem in any more depth.