* 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

* When accessing uncached media attachment, redownload it

* Prevent re-download of rejected media

* Revert "Enable UniqueRetryJobMiddleware even when called from sidekiq worker (#4836)"

This reverts commit 6859d4c0.

* Revert "Do not execute the job with the same arguments as the retry job (#4814)"

This reverts commit be7ffa2d.

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.

* Use casecmp() instead of casecmp?() for now

casecmp?() is only available in ruby 2.4.0.  Users running earlier ruby versions
would see errors, e.g., running
RAILS_ENV=production rails mastodon:maintenance:remove_deprecated_preview_cards.

* Correctly check whether casecmp() returns 0

The path template of the attached files must explicitly be defined because
it is contradicting to the name of the class.

* Make PreviewCard records reuseable between statuses

**Warning!** Migration truncates preview_cards tablec

* Allow a wider thumbnail for link preview, display it in horizontal layout (#4648)

* Delete preview cards files before truncating

* Rename old table instead of truncating it

* Add mastodon:maintenance:remove_deprecated_preview_cards

* Ignore deprecated_preview_cards in schema definition

* Fix null behaviour

* Add handling of Linked Data Signatures in payloads

* Add a way to sign JSON, fix canonicalization of signature options

* Fix signatureValue encoding, send out signed JSON when distributing

* Add missing security context

* Add Mastodon::Source.url

* Update spec

* Refactor

Move things frmo Mastodon::Source to Mastodon::Version

* ActivityPub migration procedure

Once one account is detected as going from OStatus to ActivityPub,
invalidate WebFinger cache for other accounts from the same domain

* Unsubscribe from PuSH updates once we receive an ActivityPub payload

* Re-subscribe to PuSH unless already unsubscribed, regardless of protocol

* Move clean up of unconfirmed users to sidekiq-scheduler

* mastodon:daily is now deprecated

* Use the same emoji data on the frontend and backend

* Move emoji.json to repository, add tests

This way you don't need to install node dependencies if you only
want to run Ruby code

* Check table existence on prepare_for_foreign_keys

* Remove trailing whitespace

* Add Rake task for generate VAPID key

* edit config/initializers/vapid.rb

Can be filtered by a specific domain
Resolves #2292

* Redesign the landing page, mount public timeline on it

* Adjust the standalone mounted component to the lacking of router

* Adjust auth layout pages to new design

* Fix tests

* Standalone public timeline polling every 5 seconds

* Remove now obsolete translations

* Add responsive design for new landing page

* Address reviews

* Add floating clouds behind frontpage form

* Use access token from public page when available

* Fix mentions and hashtags links, cursor on status content in standalone mode

* Add footer link to source code

* Fix errors on pages that don't embed the component, use classnames

* Fix tests

* Change anonymous autoPlayGif default to false

* When gif autoplay is disabled, hover to play

* Add option to hide the timeline preview

* Slightly improve alt layout

* Add elephant friend to new frontpage

* Display "back to mastodon" in place of "login" when logged in on frontpage

* Change polling time to 3s

https://github.com/codeclimate/codeclimate-rubocop/blob/08f8de84ebfb39caa96391e23816877278f6441c/Gemfile.lock#L38
Code Climate is using RuboCop v0.46.0.

Change several rules to maintain compatibility.

* Add rake task to prepare database for foreign keys introduced by #3562

* Fix typo

* Do not delete OAuth values where NULL values may be permitted

* Fix typo