Merge branch 'feature/edit-proposal' of github.com:loomio/loomio into feature/edit-proposal-notifies-users-who-have-voted

* 'feature/edit-proposal' of github.com:loomio/loomio:
  Add edit functionality to motion with revision history

Conflicts:
	app/assets/javascripts/motions.js.coffee
	app/assets/stylesheets/motions.css.scss
	app/controllers/motions_controller.rb
	app/views/motions/_form.html.haml
	config/locales/en.yml
	features/motions/edit_motion.feature
	features/step_definitions/edit_motion_steps.rb
	spec/controllers/motions_controller_spec.rb