Bug resolved in collection module

There was a bug in collection module, when you go for making some collection of resource you get an error when your collection list (i.e right drawer)is empty. Also at creating collection first time for new resource. 

Now issue is resolved
Modification in : 
```
base.html     
ajax_view.py --> select_ drawer method
```
Script added in base.html which was misplaced.
Added condition in collection widget when it goes for ajax call for selecting the resources.