Add Info and Link at Manage Item (oc-admin)

This is just to make admin life easier. 
At admin item listings, add total posted item per user / email and link to Ban and Edit User.

![screen shot 2013-10-09 at 8 04 11 pm](https://f.cloud.github.com/assets/4693418/1297495/77746c22-30e3-11e3-9927-2808b3321560.png)