Added working Thumb Up, Thumb Down feature. 

It successfully "loves","bans", and "unrates" when toggled.

It could be cleaned up to work with the already existing
icon-recognition functions, but that is a styling issue left for
later.

EDIT: Annd, I just remembered the proper image is not initially set.

The thumb icon is public domain from wikimedia:
http://commons.wikimedia.org/wiki/File:Symbol_thumbs_up.svg

I know I theoretically could have attached the pull request to #62 , but I couldn't get it to work quickly.