Revert "Finish log in/log out"

This reverts commit 3e17e8c78a5c0c2ff5d492af51a832341e642b54.

	modified:   app/assets/javascripts/application.js
	deleted:    app/assets/javascripts/sessions.js.coffee
	modified:   app/assets/stylesheets/custom.css.scss
	deleted:    app/assets/stylesheets/sessions.css.scss
	modified:   app/controllers/application_controller.rb
	deleted:    app/controllers/sessions_controller.rb
	modified:   app/controllers/users_controller.rb
	deleted:    app/helpers/sessions_helper.rb
	modified:   app/models/user.rb
	modified:   app/views/layouts/_header.html.erb
	deleted:    app/views/sessions/new.html.erb
	modified:   config/routes.rb
	deleted:    db/migrate/20141027125043_add_remember_digest_to_users.rb
	modified:   db/schema.rb
	deleted:    test/controllers/sessions_controller_test.rb
	deleted:    test/helpers/sessions_helper_test.rb
	deleted:    test/integration/users_login_test.rb
Finish log in/log out