Unsubscribe (delete account) with one click

Well, two actually. The "Delete Account" link takes you to a "are you sure?" kind of page. Closes Issue #135. Let me know if there's anything else that needs to be done on this before getting merged.

>![screen shot 2013-11-07 at 8 26 32 am](https://f.cloud.github.com/assets/30456/1491930/a6eb4296-47b8-11e3-827b-22124300354f.png)