* Responsively enforce 16:9 ratio on all media thumbnails in web UI
Also change video player behaviour to "contain" rather than
"cover" videos that don't fit the ratio, unlike images and GIFs,
it's expected that a video is shown fully.
* Fix spacing issues and remove floor
* Remove floor
* Add focus param to media API, center thumbnails on focus point
* Add UI for setting a focal point
* Improve focal point icon on upload item
* Use focal point in upload preview
* Add focalPoint property to ActivityPub
* Don't show focal point button for non-image attachments
* 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
* Redesign video player
* Use new video player on static public pages too
* Use media gallery component on static public pages too
* Pause video when hiding it
* Full-screen sizing on WebKit
* Add aria labels to video player buttons
* Display link card on public status page
* Fix fullscreen from modal sizing issue
* Remove contain: strict property to fix fullscreen from columns
