fix($dirty): fix dirty usage

fixes #238
closes #239

Author: MrMartiniMo

Diff for: dist/tinymce.min.js

@@ -63,8 +63,10 @@ angular.module('ui.tinymce', [])
 	        $timeout.cancel(debouncedUpdateTimer);
 	         debouncedUpdateTimer = $timeout(function() {
               return (function(ed) {
-                ed.save();
-                updateView(ed);
+                if (ed.isDirty()) {
+                  ed.save();
+                  updateView(ed);
+                }
               })(ed);
             }, debouncedUpdateDelay);
           };

Diff for: src/tinymce.js

@@ -101,6 +101,17 @@ describe('uiTinymce', function () {
         done();
       }, 100);
     });
+    it('shouldn\'t make the form dirty', function(done) {
+      compile();
+      setTimeout(function() {
+        scope.foo = text;
+        scope.$apply();
+
+        expect(directiveElement.controller('form').$dirty).toBe(false);
+
+        done();
+      });
+    });
     // TODO: Fix test
     xit('should handle undefined gracefully', function(done) {
       compile();