Allow subscription to be created and deleted without refreshing page

https://trello.com/c/l2vLI2yj/353-address-repos-with-subscriptions-that-weren-t-enabled
Allow non-paying users to unsubscribe

https://trello.com/c/SrdebCDE/345-ensure-that-only-repo-payer-can-disable-it
Add JavaScript support

https://trello.com/c/LQsUqhYU/179-support-javascript

* Use JSHint to review JavaScript code
* Allow users to configure JavaScript style guide
* Use jshintrb gem to easily use JSHint in Ruby
Fix style guides link
Specify indentation preference for JavaScript
Merge pull request #405 from soulcutter/patch-1

Update style guide path.
Merge remote-tracking branch 'upstream/master'

Conflicts:
	app/assets/javascripts/directives/repo.js.coffee.erb
Merge branch 'master' of github.com:dobtco/hound