adds user model
adds user authentication
adds playlist model
adds playlist show, new, create actions
adds nonfunctioning edit, update, destroy actions to playlist
changes application.rb to prevent assets precompile to get heroku working...?
adds song model and user / playlist associations
fixed auth token
fixes song migration
Merge branch 'playlists'
minor changes to playlist show page
adds mass playlist song creation
playlists can be tagged
minor view refactoring