Subreddit shortcuts edit/delete button


![screen shot 2014-09-12 at 2 25 27 pm](https://cloud.githubusercontent.com/assets/455632/4255212/a27094da-3ab2-11e4-9674-4c446422af34.png)
![screen shot 2014-09-12 at 2 25 40 pm](https://cloud.githubusercontent.com/assets/455632/4255213/a2778f56-3ab2-11e4-92c1-063371688516.png)

Adds a dropdown to all subreddit shortcuts with edit/delete buttons.  (optional, default on)

Adds a delete button to subreddit shortcut editor