* Do not debounce emoji search

* Make autosuggestions appear sooner

* Upgrade to React 16.0.0

* Disable some uncritical tests while chai-enzyme remains incompatible

* Remove react-sizeme

* Fix aspect ratio in "sensitive" mode

Translate "about" page, several settings pages, data export/import,
sessions overview, authorized followers page, account deletion page.

More consistent use of words:
- A toot is a Beitrag.
- An account is a Konto.

Some small improvements.

ABRACA-HRRRRRRRRRRRNGGGGGGGHHH!!!!!!!!!!!!!!!!!!!

- A successful delivery cancels it out
- An incoming delivery from account of the inbox cancels it out

Blaze it

I see no reason to allow more than that. Usually a redirect is
HTTP->HTTPS, then maybe URL structure changed, but more than that
is highly unlikely to be a legitimate use case.

Create activerecord.de.yml (50%)
Update devise.de.yml
Update doorkeeper.de.yml (100%)
Update simple_form.de.yml (100%)

* Improve performance of modal and swipe animations

* Fix eslint issues

If the signature could not be verified and the webfinger of the account
was last retrieved longer than the cache period, try re-resolving the
account and then attempting to verify the signature again

* 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

This reverts commit c89cce0219.

This reverts commit fa3587645da228e93767b245eeadbd668bc6cd38, reversing
changes made to 15c9c2fd7e.

* Update Yarn to version 1.1.0

* remove hard-coding

* Remove web UI warnings about OStatus privacy

* yarn run manage:translations

Call to warden.authenticate! in resource_owner_from_credentials would
make the request redirect to sign-in path, which is a bad response for
apps. Now bad credentials just return nil, which leads to HTTP 401
from Doorkeeper. Also, accounts with enabled 2FA cannot be logged into
this way.

* i18n: Update Polish translation

* i18n: Update Polish translation

- Previously they wouldn't receive it unless they were author's
  followers
- Skip unpush from public/hashtag timelines if status wasn't
  public in the first place

- 500.html generated with admin-set default locale if set
- Error page `<title>` includes Mastodon site title
- 500 title changed to "This page is not
  correct" (ref: <https://www.youtube.com/watch?v=2VCAP_seh1A>)
- 500 content appended with "on our end" to make clear it's
  not user's fault