make xhr.cache optionally synchronous

- add `sync` flag xhr.cache
- change ng:include to use the sync flag
- change ng:view to use the sync flag

The end result is that there are fewer repaints in the browser,
which means less "blinking" that user sees.

test/service/xhr.cacheSpec.js

@@ -107,6 +107,22 @@ describe('$xhr.cache', function() {
   });
 
 
+  it('should call callback synchronously when sync flag is on', function() {
+    $browserXhr.expectGET('/url').respond('+');
+    cache('GET', '/url', null, callback, false, true);
+    expect(log).toEqual(''); //callback hasn't executed
+
+    $browserXhr.flush();
+    expect(log).toEqual('"+";'); //callback has executed
+
+    cache('GET', '/url', null, callback, false, true);
+    expect(log).toEqual('"+";"+";'); //callback has executed
+
+    $browser.defer.flush();
+    expect(log).toEqual('"+";"+";'); //callback was not called again any more
+  });
+
+
   it('should call eval after callbacks for both cache hit and cache miss execute', function() {
     var eval = this.spyOn(scope, '$eval').andCallThrough();
 

test/widgetsSpec.js

@@ -610,7 +610,6 @@ describe("widget", function(){
       scope.url = 'myUrl';
       scope.$service('$xhr.cache').data.myUrl = {value:'{{name}}'};
       scope.$eval();
-      scope.$service('$browser').defer.flush();
       expect(element.text()).toEqual('misko');
       dealoc(scope);
     });
@@ -623,7 +622,6 @@ describe("widget", function(){
       scope.url = 'myUrl';
       scope.$service('$xhr.cache').data.myUrl = {value:'{{name}}'};
       scope.$eval();
-      scope.$service('$browser').defer.flush();
 
       expect(element.text()).toEqual('igor');
 
@@ -640,7 +638,6 @@ describe("widget", function(){
       scope.url = 'myUrl';
       scope.$service('$xhr.cache').data.myUrl = {value:'{{c=c+1}}'};
       scope.$eval();
-      scope.$service('$browser').defer.flush();
 
       // this one should really be just '1', but due to lack of real events things are not working
       // properly. see discussion at: http://is.gd/ighKk
@@ -657,7 +654,6 @@ describe("widget", function(){
       scope.url = 'myUrl';
       scope.$service('$xhr.cache').data.myUrl = {value:'my partial'};
       scope.$eval();
-      scope.$service('$browser').defer.flush();
       expect(element.text()).toEqual('my partial');
       expect(scope.loaded).toBe(true);
       dealoc(element);