Quiz management functionality added

Added functionality for Quiz workflow (creation, editing, review) and comments managing.
Added QuizForm Directive and QuizResource.
![image](https://cloud.githubusercontent.com/assets/2779240/5183562/d063da92-74b8-11e4-8360-80eb4d318b20.png)

```
subCatsArray.filter(function(subcat){
  return $scope.selectedSubcat == subcat;
});
```