fix #1920

In rails 3 the annotation route was:
```
 annotations DELETE   (/:locale)/annotations(.:format)            annotations#destroy {:locale=>/en|fr|pt/}
             GET      (/:locale)/annotations(.:format)            annotations#index {:locale=>/en|fr|pt/}
             POST     (/:locale)/annotations(.:format)            annotations#create {:locale=>/en|fr|pt/}

```

In rails 4 the annotation route becomes:
```
 annotations DELETE   (/:locale)/annotations/destroy(.:format)    annotations#destroy {:locale=>/en|fr|pt/}
             GET      (/:locale)/annotations(.:format)            annotations#index {:locale=>/en|fr|pt/}
             POST     (/:locale)/annotations(.:format)            annotations#create {:locale=>/en|fr|pt/}
```

I modified the annotation route so that it looks like the one in rails 3.