Update FeedEk.js

Modified FeedEk to return the promise object so that success/fail/progress events can be chained on. An example calling the basic FeedEk functionality, with success, fail, and progress event functions chained on.

$('#divRss').FeedEk({
    FeedUrl : 'http://rss.cnn.com/rss/edition.rss',
  }).then(function(){ /*success*/ }, function(){ /*fail*/ }, function(){ /*progress*/ });