Attachments

First stab at attachments :floppy_disk: 

![screen shot 2013-07-10 at 11 11 36 pm](https://f.cloud.github.com/assets/362783/777957/56fe69e6-e9a5-11e2-9b41-56f82be656f0.png)

**Note:** I left the commits so that it's easier to process. I can rebase if needed.

:warning: **SECURITY WARNING** :warning: right now, it's only checking the extension of the uploaded files. I'll add a mime-type check tomorrow.