FEATURE: Add Bookmarks menu to user dropdown

Add **Bookmarks** menu to user dropdown:

![bokmarks_menu](https://cloud.githubusercontent.com/assets/5732281/3250596/ba9a74c6-f1a7-11e3-9f72-35acab2441fa.png)

It will only be visible when user has Bookmarks, in case user does not have any bookmark, the bookmark menu will not be visible.