* Refactor formatter

* Move custom emoji pre-rendering logic to view helpers

* Move more methods out of Formatter

* Fix code style issues

* Remove Formatter

* Add inline poll options to RSS feeds

* Remove unused helper method

* Fix code style issues

* Various fixes and improvements

* Fix test

Fix #16217, regression from #16160

It's not useful for now, but it's required by ActivityPub

* Show badge on group actor in WebUI

* Do not notify in case of  by following group actor

* If you mention group actor, also mention group actor followers

* Relax characters that can be used in username (same as Application)

* Revert "Relax characters that can be used in username (same as Application)"

This reverts commit 7e10a137b878d0db1b5252c52106faef5e09ca4b.

* Delete display_name method

* Fix contexts not being dynamically included

Fixes #11649

* Refactor Note context in serializer

* Refactor Actor serializer

* Add profile directory to web UI

* Add a line of bio to the directory

* Add support for an instance actor

* Skip username validation for local Application accounts

* Add migration script to create instance actor

* Make Codeclimate happy

* Switch to id -99 for instance actor

* Remove unused `icon` and `image` attributes from instance actor

* Use if/elsif/else instead of return + ternary operator

* Add instance actor to fresh installs

* Use instance actor as instance representative

Use instance actor for forwarding reports, relay operations, and spam
auto-reporting.

* Seed database in test environment

* Fix single-user mode

* Fix tests

* Fix specs to accomodate for an extra `Account`

* Auto-reject follows on instance actor

Following an instance actor might make sense, but we are not handling that
right now, so auto-reject.

* Fix webfinger lookup and serialization for instance actor

* Rename instance actor

* Make it clear in the HTML view that the instance actor should not be blocked

* Raise cache time for instance actor as there's no dynamic content

* Re-use /about/more with a flash message for instance actor profile

Fix #11270

* Add ActivityPub representation for identity proofs

* Add tests

Fix #8078

When serializing an ActivityPub actor, Mastodon checks for the existence
of the avatar/header files. This is not necessary, only check if avatar/header
is set.

https://github.com/thoughtbot/paperclip/blob/fd8bf49d3895de2904b43f95d11af0736fbd0f5b/README.md#checking-a-file-exists

* Store actor type in database

* Add bot nameplate to web UI, add setting to preferences, API, AP
Fix #7365

* Fix code style issues

* Add bio fields

- Fix #3211
- Fix #232
- Fix #121

* Display bio fields in web UI

* Fix output of links and missing fields

* Federate bio fields over ActivityPub as PropertyValue

* Improve how the fields are stored, add to Edit profile form

* Add rel=me to links in fields

Fix #121

Federate custom emojis with accounts

* Federate pinned statuses over ActivityPub

* Display pinned toots in web UI

Fix #6117

* Fix migration

* Fix tests

* Update outbox_serializer.rb

* Update remove_serializer.rb

* Update add_serializer.rb

* Update fetch_featured_collection_service.rb

* Serialize moved accounts into REST and ActivityPub APIs

* Parse federated moved accounts from ActivityPub

* Add note about moved accounts to public profiles

* Add moved account message to web UI

* Fix code style issues

* Encode custom emojis as resolveable objects in ActivityPub

* Improve code style

- Fix assumption that `url` is always a string. Handle it if it's an
  array of strings, array of objects, object, or string, both for
  accounts and for objects
- `sharedInbox` is actually supposed to be under `endpoints`, handle
  both cases and adjust the serializer

See: <https://www.w3.org/wiki/Activity_Streams_extensions#as:manuallyApprovesFollowers>

Using _: property names is discouraged, as in the future,
canonicalization may throw an error when encountering that instead
of discarding it silently like it does now.

We are defining some ActivityStreams properties which we expect
to land in ActivityStreams eventually, to ensure that future versions
of Mastodon will remain compatible with this even once that happens.
Those would be `locked`, `sensitive` and `Hashtag`

We are defining a custom context inline for some properties which we
do not expect to land in any other context. `atomUri`, `inReplyToAtomUri`
and `conversation` are part of the custom defined OStatus context.

* Add ActivityPub inbox

* Handle ActivityPub deletes

* Handle ActivityPub creates

* Handle ActivityPub announces

* Stubs for handling all activities that need to be handled

* Add ActivityPub actor resolving

* Handle conversation URI passing in ActivityPub

* Handle content language in ActivityPub

* Send accept header when fetching actor, handle JSON parse errors

* Test for ActivityPub::FetchRemoteAccountService

* Handle public key and icon/image when embedded/as array/as resolvable URI

* Implement ActivityPub::FetchRemoteStatusService

* Add stubs for more interactions

* Undo activities implemented

* Handle out of order activities

* Hook up ActivityPub to ResolveRemoteAccountService, handle
Update Account activities

* Add fragment IDs to all transient activity serializers

* Add tests and fixes

* Add stubs for missing tests

* Add more tests

* Add more tests

* Improve webfinger templates and make tests more flexible

* Clean up AS2 representation of actor

* Refactor outbox

* Create activities representation

* Add representations of followers/following collections, do not redirect /users/:username route if format is empty

* Remove unused translations

* ActivityPub endpoint for single statuses, add ActivityPub::TagManager for better
URL/URI generation

* Add ActivityPub::TagManager#to

* Represent all attachments as Document instead of Image/Video specifically
(Because for remote ones we may not know for sure)

Add mentions and hashtags representation to AP notes

* Add AP-resolvable hashtag URIs

* Use ActiveModelSerializers for ActivityPub

* Clean up unused translations

* Separate route for object and activity

* Adjust cc/to matrices

* Add to/cc to activities, ensure announce activity embeds target status and
not the wrapper status, add "id" to all collections