Only CRUD permissions should be displayed on permission page

(Previous PR was merged into a merged branch, so here's a new PR)

#4693 
#4636


Using default roles and permissions:
![crud_only2](https://f.cloud.github.com/assets/3273122/1724337/038a5eea-626e-11e3-95bb-4aa4b36a443f.png)


Using custom roles and permissions:
![crud_only1](https://f.cloud.github.com/assets/3273122/1724336/fe987bba-626d-11e3-8d76-f1d2986fcb7b.png)