Attachments View Implementation

This is the attachments view -- add attachments to it and it displays them inline, scrolling horizontally when there are too many. When you click on an attachment it opens in a fullscreen dialog. Lastly, you can have it show an add attachment button, and receive a callback when the user clicks that.

#145 Should go through first.
This will probably cause problems because this view needs to support answers as well. That's why I wanted the fields instead.