fix(jqLite): deregister special mouseenter / mouseleave events correctly

Closes angular#12795
Closes angular#12799

Author: petebacondarwin

src/jqLite.js

@@ -850,13 +850,13 @@ forEach({
     var types = type.indexOf(' ') >= 0 ? type.split(' ') : [type];
     var i = types.length;
 
-    var addHandler = function(type, specialHandlerWrapper) {
+    var addHandler = function(type, specialHandlerWrapper, noEventListener) {
       var eventFns = events[type];
 
       if (!eventFns) {
         eventFns = events[type] = [];
         eventFns.specialHandlerWrapper = specialHandlerWrapper;
-        if (type !== '$destroy') {
+        if (type !== '$destroy' && !noEventListener) {
           addEventListenerFn(element, type, handle);
         }
       }
@@ -868,6 +868,7 @@ forEach({
       type = types[i];
       if (MOUSE_EVENT_MAP[type]) {
         addHandler(MOUSE_EVENT_MAP[type], specialMouseHandlerWrapper);
+        addHandler(type, undefined, true);
       } else {
         addHandler(type);
       }

test/jqLiteSpec.js

@@ -1469,6 +1469,20 @@ describe('jqLite', function() {
       expect(onMouseleave).toHaveBeenCalledOnce();
     });
 
+    it('should call a `mouseenter/leave` listener when manually triggering the event', function() {
+      var aElem = jqLite(a);
+      var onMouseenter = jasmine.createSpy('mouseenter');
+      var onMouseleave = jasmine.createSpy('mouseleave');
+
+      aElem.on('mouseenter', onMouseenter);
+      aElem.on('mouseleave', onMouseleave);
+
+      aElem.triggerHandler('mouseenter');
+      expect(onMouseenter).toHaveBeenCalledOnce();
+
+      aElem.triggerHandler('mouseleave');
+      expect(onMouseleave).toHaveBeenCalledOnce();
+    });
 
 
     it('should deregister specific listener within the listener and call subsequent listeners', function() {