sort albums/index in descending points order (for now)
create UserAlbumVotes and relevant associations
split UserAlbumVotes into separate Upvotes and Downvotes
rename upvote/downvote columns and fix albums#upvote, albums#downvote
refactor user, album associations
update TODOs
create UserCommentUpvotes/Downvotes + associations + controller actions
Merge branch 'votes'

Conflicts:
	README.md
	app/views/albums/index.html.erb