Bug resolved. Breadcrumbs for collection navigation implemented successfully

Implemented logic for manipulation on breadcrumbs list, for easy navigation between collection items of resource

Modification in : 
```
page.py  -->  Breadcrumbs list creates for first time when user visits on Page Details
ajax_views.py  -->  logic included for manipulation(adding and deleting list items) with breadcrumbs list 
collection_ajax_view.html  --> This template shows breadcrumbs list on top of resource collection, along with included ajax requests which handles breadcrumbs list manipulations   
```