feat($timeout): add $timeout service that supersedes $defer

$timeout has a better name ($defer got often confused with something related to $q) and
is actually promise based with cancelation support.

With this commit the $defer service is deprecated and will be removed before 1.0.

Closes #704, #532

test/ngMock/angular-mocksSpec.js

@@ -313,6 +313,23 @@ describe('ngMock', function() {
   });
 
 
+  describe('$timeout', function() {
+    it('should expose flush method that will flush the pending queue of tasks', inject(
+        function($timeout) {
+      var logger = [],
+          logFn = function(msg) { return function() { logger.push(msg) }};
+
+      $timeout(logFn('t1'));
+      $timeout(logFn('t2'), 200);
+      $timeout(logFn('t3'));
+      expect(logger).toEqual([]);
+
+      $timeout.flush();
+      expect(logger).toEqual(['t1', 't3', 't2']);
+    }));
+  });
+
+
   describe('angular.mock.dump', function(){
     var d = angular.mock.dump;