[MastoAPI] Add switching of frontend flavours

See merge request pleroma/pleroma!807

Follow request count

See merge request pleroma/pleroma!817

Add option to return all friends in twitter api.

Closes #602

See merge request pleroma/pleroma!833

mix.exs: Add docs/Clients.md to docs.extras

See merge request pleroma/pleroma!835

# Conflicts:
#   mix.exs

Docker speedup

See merge request pleroma/pleroma!837

Remove a limit on attachments in Mastodon API and document the changes in responses from vanilla Mastodon

See merge request pleroma/pleroma!834

Fix recipient count in hellthread policy

See merge request pleroma/pleroma!836

[ci skip]

Add a section on how to identify a pleroma instance, clarify that post upload limit is not capped too

Add optional welcome message.

See merge request pleroma/pleroma!832

Remove a limit on attachments in Mastodon API and document the changes in responses from vanilla mastodon

Mainly useful for user export.

oauth: never use base64 padding when returning tokens to applications

See merge request pleroma/pleroma!825

Hellthread filter fix

Closes #634

See merge request pleroma/pleroma!831

activitypub: correctly handle bare URIs in user lookup

Closes #645

See merge request pleroma/pleroma!829

`approve_friend_request`, and `deny_friend_request` actions.
Add follow_request_count to the user view.

get_or_fetch() handles the nickname verses URI differences transparently.

activitypub transmogrifier: fix reserialization edge cases

See merge request pleroma/pleroma!826

Fix S3 links encoding in Mediaproxy

Closes #580

See merge request pleroma/pleroma!828

Fix credo issues in ./test

See merge request pleroma/pleroma!808