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

When colon appears end of line, skiped all character containing unicode emojis. Fixed.
https://github.com/tootsuite/mastodon/pull/5016#issuecomment-331012008

* Reduce wasted renders for column_loading.js

* Use defaultProps

* Fix JavaScript interface with long IDs

Somewhat predictably, the JS interface handled IDs as numbers, which in
JS are IEEE double-precision floats. This loses some precision when
working with numbers as large as those generated by the new ID scheme,
so we instead handle them here as strings. This is relatively simple,
and doesn't appear to have caused any problems, but should definitely
be tested more thoroughly than the built-in tests. Several days of use
appear to support this working properly.

BREAKING CHANGE:

The major(!) change here is that IDs are now returned as strings by the
REST endpoints, rather than as integers. In practice, relatively few
changes were required to make the existing JS UI work with this change,
but it will likely hit API clients pretty hard: it's an entirely
different type to consume. (The one API client I tested, Tusky, handles
this with no problems, however.)

Twitter ran into this issue when introducing Snowflake IDs, and decided
to instead introduce an `id_str` field in JSON responses. I have opted
to *not* do that, and instead force all IDs to 64-bit integers
represented by strings in one go. (I believe Twitter exacerbated their
problem by rolling out the changes three times: once for statuses, once
for DMs, and once for user IDs, as well as by leaving an integer ID
value in JSON. As they said, "If you’re using the `id` field with JSON
in a Javascript-related language, there is a very high likelihood that
the integers will be silently munged by Javascript interpreters. In most
cases, this will result in behavior such as being unable to load or
delete a specific direct message, because the ID you're sending to the
API is different than the actual identifier associated with the
message." [1]) However, given that this is a significant change for API
users, alternatives or a transition time may be appropriate.

1: https://blog.twitter.com/developer/en_us/a/2011/direct-messages-going-snowflake-on-sep-30-2011.html

* Additional fixes for stringified IDs in JSON

These should be the last two. These were identified using eslint to try
to identify any plain casts to JavaScript numbers. (Some such casts are
legitimate, but these were not.)

Adding the following to .eslintrc.yml will identify casts to numbers:

~~~
  no-restricted-syntax:
  - warn
  - selector: UnaryExpression[operator='+'] > :not(Literal)
    message: Avoid the use of unary +
  - selector: CallExpression[callee.name='Number']
    message: Casting with Number() may coerce string IDs to numbers
~~~

The remaining three casts appear legitimate: two casts to array indices,
one in a server to turn an environment variable into a number.

* Back out RelationshipsController Change

This was made to make a test a bit less flakey, but has nothing to
do with this branch.

* Change internal streaming payloads to stringified IDs as well

Per
https://github.com/tootsuite/mastodon/pull/5019#issuecomment-330736452
we need these changes to send deleted status IDs as strings, not
integers.

* Add support for selecting a theme

* Fix codeclimate issues

* Look up site default style if current user is not available due to e.g. not being logged in

* Remove outdated comment in common.js

* Address requested changes in themes PR

* Fix codeclimate issues

* Explicitly check current_account in application controller and only check theme availability if non-nil

* codeclimate

* explicit precedence with &&

* Fix code style in application_controller according to @nightpool's suggestion, use default style in embedded.html.haml

* codeclimate: indentation + return

Additionally, this restores previous background / text color for media spoiler.

* Custom emoji

- In OStatus: `<link rel="emoji" name="coolcat" href="http://..." />`
- In ActivityPub: `{ type: "Emoji", name: ":coolcat:", href: "http://..." }`
- In REST API: Status object includes `emojis` array (`shortcode`, `url`)
- Domain blocks with reject media stop emojis
- Emoji file up to 50KB
- Web UI handles custom emojis
- Static pages render custom emojis as `<img />` tags

Side effects:

- Undo #4500 optimization, as I needed to modify it to restore
  shortcode handling in emojify()
- Formatter#plaintext should now make sure stripped out line-breaks
  and paragraphs are replaced with newlines

* Fix emoji at the start not being converted

* So Spanish. Much changes. Wow.

* Some little fixes

* Updated es.yml, and fixed some ortographical errors

* Some little changes to simple_form.es.yml

* Yeah, so much translations

* Spanish e-mail messages

* Remove unused message

Limiting allowed characters in the last character of the URL is came from twitter-text, but underscore is allowed on there, and Mastodon before #4941.