Adding a spinner to the Future theme
Bring in https://github.com/HubSpot/messenger/commit/2eed64644aec05bf27532e4cfc5f6ff6847fcd0e from master
Bring in https://github.com/HubSpot/messenger/commit/2eed64644aec05bf27532e4cfc5f6ff6847fcd0e from master (part deux)
Merge branch 'master' into message_spinner

Conflicts:
	build/js/messenger.js
Merge branch 'message_spinner'

Conflicts:
	build/css/messenger-theme-future.css
	src/sass/messenger-theme-future.sass
Add classes
Make id apply to all messages
Merge branch 'message_spinner'

Conflicts:
	build/css/messenger-theme-future.css
	build/js/messenger.js
	src/coffee/messenger.coffee