Added uploads through carrierwave
Added changes_solutions feature to exercises
Added markItUp to all relevant text areas (no image dialog yet)
Added attachments dialog with AJAX image uploading
Added submit_classes to everything except doorkeeper; added attachments list and dialog to solutions
DRYed up most migrations
DRYed up exercise and solution new_version and derive actions and improved routing
Merge branch 'master' of github.com:openstax/exercises into jpslav_work_1

Conflicts:
	Gemfile
	Gemfile.lock
	app/assets/stylesheets/application.css.scss
	app/views/devise/confirmations/new.html.erb
	app/views/devise/passwords/edit.html.erb
	app/views/devise/passwords/new.html.erb
	app/views/devise/registrations/edit.html.erb
	app/views/devise/registrations/new.html.erb
	app/views/devise/sessions/new.html.erb
	app/views/devise/unlocks/new.html.erb
	app/views/shared/_exercises_search.html.erb
	config/routes.rb
	db/migrate/20130611171216_devise_create_users.rb
	db/migrate/20130621174736_add_fields_to_users.rb
	db/migrate/20130713013656_commontator_install.commontator.rb
	db/migrate/20130713013656_install.commontator.rb
	db/migrate/20131104231845_install_commontator.commontator.rb
	db/schema.rb