Commit 3041a8f22c08df96ce5870e099349794df901d9f

Add loading of plugin without callback

  Previously, one had to load plugin providing a callback. Make it optional at
backend. Front end has no input for callback. Have to fix that.
  
7676 var callback = this.get('callback');
7777 script.src = this.get('src');
7878 document.body.appendChild(script);
79 script.onload = function() {
80 eval(callback);
81 };
79 if(callback) {
80 script.onload = function() {
81 eval(callback);
82 };
83 }
8284 }
8385 else if(this.get('src').match(/\.css/)) {
8486 var link = document.createElement('link');