* Update translation files

Signed-off-by: Marcin Mikołajczak <me@m4sk.in>

* i18n: Update Polish translation

Signed-off-by: Marcin Mikołajczak <me@m4sk.in>

* Toggle contain:strict on fullscreen

* Fix scss lint issue

* fix scss whitespace lint issue

* Improve privacy dropdown, remove react-simple-dropdown dependency

* Animate privacy warning

* Fix react-router-scroll

* Add image descriptions to `title` attribute to view on mouse hover/long-press.

* Too many title properties may spoil the broth.

* unite loop process
* add hint for original emojifier

* 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.

Blaze it

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

* 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

* Remove web UI warnings about OStatus privacy

* yarn run manage:translations

- 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

A new rake task emojis:generate downloads a full list of valid
unicode sequences from unicode.org and checks it against existing
Twemoji files, finally generating a map from each sequence to the
existing file (e.g. when there's multiple ways an emoji can be
expressed). The map is dumped into app/javascript/mastodon/emoji_map.json

That file is loaded by emojione_light.js (now a misnomer) which
decorates it further with shortcodes taken from emoji-mart's index.

* In detail status view, display attachment uncropped if there's only one

* Make media spoiler the size of the media it hides, enable on static

630px = Drawer + 1 Column

* Fix numbers in accounts columns

* Support edge compact-header

* Add emoji autosuggest

Some credit goes to glitch-soc/mastodon#149

* Remove server-side shortcode->unicode conversion

* Insert shortcode when suggestion is custom emoji

* Remove remnant of server-side emojis

* Update style of autosuggestions

* Fix wrong emoji filenames generated in autosuggest item

* Do not lazy load emoji picker, as that no longer works

* Fix custom emoji autosuggest

* Fix multiple "Custom" categories getting added to emoji index, only add once

* Switch from EmojiOne to Twemoji, different emoji picker

* Make emoji-mart use a local spritesheet

* Fix emojify test

* yarn manage:translations

* Make dropdowns render into portal, expand animation

* Improve actions modal style