* Fix#117 - Add ability to specify alternative text for media attachments
- POST /api/v1/media accepts `description` straight away
- PUT /api/v1/media/:id to update `description` (only for unattached ones)
- Serialized as `name` of Document object in ActivityPub
- Uploads form adjusted for better performance and description input
* Add tests
* Change undo button blend mode to difference
* Move ApiController to Api/BaseController
* API controllers inherit from Api::BaseController
* Add coverage for various error cases in api/base controller
resources that require a user context vs those that don't (such as public timeline)
/api/v1/statuses/public -> /api/v1/timelines/public
/api/v1/statuses/home -> /api/v1/timelines/home
/api/v1/statuses/mentions -> /api/v1/timelines/mentions
/api/v1/statuses/tag/:tag -> /api/v1/timelines/tag/:tag