* Support OpenGraph video embeds

It's not really OpenGraph, it's twitter:player property, but it's
not OEmbed so that fits. For example, this allows Twitch clips to
be displayed as embeds.

Also, fixes glitch-soc/mastodon#135

* Fix invalid OpenGraph cards being saved through attaching and
revisit URLs after 14 days

* Redesign video player

* Use new video player on static public pages too

* Use media gallery component on static public pages too

* Pause video when hiding it

* Full-screen sizing on WebKit

* Add aria labels to video player buttons

* Display link card on public status page

* Fix fullscreen from modal sizing issue

* Remove contain: strict property to fix fullscreen from columns

* Make RefollowWorker ActivityPub-only to avoid potential identifier mismatches

* Don't call RefollowWorker on new accounts

* Improve OpenGraph tags for about pages

* Add thumbnail admin setting

* Fix error

* Fix up

* Update doorkeeper.nl.yml

* Update nl.yml

* Update simple_form.nl.yml

* Update nl.json

* Update en.json

* Update en.json

* Update nl.json

* Fix ActivityPub handling of replies when LOCAL_DOMAIN ≠ WEB_DOMAIN (#4895)

For all intents and purposes, `local_url?` is used to check if an URL refers
to the Web UI or the various API endpoints of the local instances. Those things
reside on `WEB_DOMAIN` and not `LOCAL_DOMAIN`.

* Change local_url? spec, as all URLs handled by Mastodon are based on WEB_DOMAIN

* Whenever a remote keypair changes, unfollow them and re-subscribe to them

In Mastodon (it could be different for other OStatus or AP-enabled software),
a keypair change is indicative of whole user (or instance) data loss. In this
situation, the “new” user might be different, and almost certainly has an empty
followers list. In this case, Mastodon instances will disagree on follower
lists, leading to unreliable delivery and “shadow followers”, that is users
believed by a remote instance to be followers, without the affected user
knowing.

Drawbacks of this change are:
1. If an user legitimately changes public key for some reason without losing
   data (not possible in Mastodon at the moment), they will have their remote
   followers unsubscribed/re-subscribed needlessly.
2. Depending of the number of remote followers, this may generate quite some
   traffic.
3. If the user change is an attempt at usurpation, the remote followers will
   unknowingly follow the usurper. Note that this is *not* a change of
   behavior, Mastodon already behaves like that, although delivery might be
   unreliable, and the usurper would not have known the former user's
   followers.

* Rename ResubscribeWorker to RefollowWorker

* Process followers in batches

This PR adds section for protocol specific information, then always show
both of OStatus and ActivityPub. Specifically, this will help admins to
check PuSH subscription status and unsubscribe manually, even `protocol`
has been changed.

This also includes below changes:

* Add `overflow: hidden` to prevent float leaking
* Add missing fields for ActivityPub

- Return all images as og:image
- Return videos as og:image (preview) and og:video
- Return profile:username on profiles

They are marked as read-only by Rails, but we know what we are doing,
so we are un-marking them as such.

The mastodon:maintenance:update_counter_caches task is not really
supposed to be run anymore (it was a one-time thing during an upgrade)
however, just in case, I have modified it to not touch ActivityPub
accounts.

Also, no point writing to logger from these rake tasks, since they
are not to be run from cron. Better to give stdout feedback.

* devise.pt-BR.yml now fully translated

* pt-BR.json now fully translated

* pt-BR.yml partially translated; 46 lines left

* pt-BR.yml now fully translated

* simple_form.pt-BR.yml fully translated

* doorkeeper.pt-BR.yml now fully translated

* E-mail instructions on app/views/user_mailer added and fully translated

* PT-BR translation for #4871

* Deleted an unwanted caracter on pt-BR.yml

* Fixing typos on pt-BR.yml

* Added translation for Pinned toots tab on pt-BR.json

* Added missing translation for navigation_bar.pins

* l10n: update Persian translation

* l10n: fix missing Persian translation

When a new user confirms their e-mail, bootstrap their home timeline
by automatically following a set of accounts. By default, all local
admin accounts (that are unlocked). Can be customized by new admin
setting (comma-separated usernames, local and unlocked only)