fix($animate): don't force animations to be enabled

The way that enabling of animations was set up, made it impossible to inject a
module into the bootstrap to disable animations for things like end 2 end tests.
Now animations are temporarily blocked by setting the animation state to RUNNING
during bootstrap, which allows the developer to permanently disable at any point
by calling $animate.enabled(false).

Author: IgorMinar

src/Angular.js

@@ -1207,7 +1207,6 @@ function bootstrap(element, modules) {
           element.data('$injector', injector);
           compile(element)(scope);
         });
-        animate.enabled(true);
       }]
     );
     return injector;

src/ngAnimate/animate.js

@@ -256,13 +256,18 @@ angular.module('ngAnimate', ['ng'])
     var ELEMENT_NODE = 1;
     var NG_ANIMATE_STATE = '$$ngAnimateState';
     var NG_ANIMATE_CLASS_NAME = 'ng-animate';
-    var rootAnimateState = {disabled:true};
+    var rootAnimateState = {running: true};
 
     $provide.decorator('$animate', ['$delegate', '$injector', '$sniffer', '$rootElement', '$timeout', '$rootScope', '$document',
                             function($delegate,   $injector,   $sniffer,   $rootElement,   $timeout,   $rootScope,   $document) {
 
       $rootElement.data(NG_ANIMATE_STATE, rootAnimateState);
 
+      // disable animations during bootstrap, but once we bootstrapped, enable animations
+      $rootScope.$$postDigest(function() {
+        rootAnimateState.running = false;
+      });
+
       function lookup(name) {
         if (name) {
           var matches = [],