* Add MVP of notification subscriptions
* Add rate limiting for notification subscriptions
* Show modal for logged out users on subscribe click
* Add enter key functionality for checkbox
* Add relationships for notification subscriptions
* Add model test for notification subscription
* Deprecated article mutes in favor of notification subscriptions
* Deprecated comment mutes in favor of notification subscriptions
* Move comment muting tests and logic over
* Merge comment and article muting into subscriptions
* Remove redundant check
* Use database to check for rate limit instead of cache
* Test for subscriptions handling notifications properly
* Fix notification model spec for subscriptions
* Fix tests for subscriptions
* Remove rate limiting
* Properly handle logged out users getting subscription status
* Fix test for new pattern
* Update reserved words
* Add config column to notification subscriptions
* Add logic for top level config and move tests
* Test for top level subscribers getting notified
* Fix logic mistake oops
* Add index and refactor comment_user_ids
