fix: unbind refresh event listener

Stops memory leaks on orphan refresh event listeners.

Fixes #339
Closes #272

package.json

@@ -1,6 +1,6 @@
 {
   "name": "angular-ui-tinymce",
-  "version": "0.0.18",
+  "version": "0.0.19",
   "descriptin": "This directive allows you to add a tinymce to your form elements.",
   "author": "https://github.com/angular-ui/ui-tinymce/graphs/contributors",
   "license": "MIT",

src/tinymce.js

@@ -179,7 +179,7 @@ angular.module('ui.tinymce', [])
         // This block is because of TinyMCE not playing well with removal and
         // recreation of instances, requiring instances to have different
         // selectors in order to render new instances properly
-        scope.$on('$tinymce:refresh', function(e, id) {
+        var unbindEventListener = scope.$on('$tinymce:refresh', function(e, id) {
           var eid = attrs.id;
           if (angular.isUndefined(id) || id === eid) {
             var parentElement = element.parent();
@@ -189,6 +189,7 @@ angular.module('ui.tinymce', [])
             clonedElement.removeAttr('aria-hidden');
             tinymce.execCommand('mceRemoveEditor', false, eid);
             parentElement.append($compile(clonedElement)(scope));
+            unbindEventListener();
           }
         });