Add directive to do blocks of http-progress

Support usage like:

``` html
 <div ng-controller="SampleController">
 <div http-angular="sampleHttpRequest" class="btn btn-default" ng-show="isPending || isSuccessful">
 <div ng-if="isProgress">Big banner when working</div>
 <div class="green" ng-if="isSuccessful">It Worked!</div>
 </div>
 </div>
```
