Port 25f9ead041 to glitch-soc

Port 029943d59b to glitch-soc

Port 065b39e7a4 to glitch-soc

Port 301cbcc980 to glitch-soc

Port 65b3804a6c to glitch-soc

Port d35801aaa2 to glitch-soc

Port f8c1b32541 to glitch-soc

Port efd09e2ebb to glitch-soc

Port b972478812 to glitch-soc

Revert server-side part of 87fdd139b8

Conflicts:
- .github/ISSUE_TEMPLATE/bug_report.md
  Took our version.
- CONTRIBUTING.md
  Updated the embedded copy of upstream's version.
- README.md
  Took our version.
- app/policies/status_policy.rb
  Not a real conflict, took code from both.
- app/views/layouts/embedded.html.haml
  Added upstream's changes (dns-prefetch) and fixed
  `%body.embed`
- app/views/settings/preferences/show.html.haml
  Reverted some of upstream changes, as we have a
  page dedicated for flavours and skins.
- config/initializers/content_security_policy.rb
  Kept our version of the CSP.
- config/initializers/doorkeeper.rb
  Not a real conflict, took code from both.

Fix #8889

Fix #8741

* RTL: remove blank character inside bdi

* Update app/javascript/mastodon/components/display_name.js

Co-Authored-By: mabkenar <ampbox@gmail.com>

* Delete first 9 accounts on dead servers

* Clean up code by moving dead server culling to the end

Fixes #9045

* RTL: fix admin account avatar margin in about page

* fix code style

This uses the same logic as the status icons in the glitch flavor.

Fixes #395

Instead of leaving the toot body blank, it replaces it with a single “.” in
order for the fold/unfold CW behavior to not look *too* weird on upstream
Mastodon. Note that this does not fix upstream's CW-dropping behavior, as
that is decided at the time the toot is posted, not received.

* Fix position of the domain label

* Fix position of the domain label for RTL

- Fix color mismatch of linear gradient which assigned to "::after" pseudo class

* Bump version to 2.6.0rc1

* Update AUTHORS.md

* Update CHANGELOG.md

and use 'if' option of context block

Indeed, when the “Always enable the Content Warning field” setting is enabled,
sending a content-less toot with a CW would move the CW to the toot's content
and leave the toot not marked as sensitive.

* Do not test PAM authentication by default

* Disable PAM tests if PAM is not enabled

* Add "disable" button to report screen

* i18n-tasks remove-unused

Previously, the server would attempt taking port/socket in worker
process, and if it was taken, fail, which made the master process
create a new worker. This led to really high CPU usage if the
streaming API was started when the port or socket were not
available.

Now, before clustering (forking) into worker processes, a test
server is created and then removed to check if it can be done.

Bumps [strong_migrations](https://github.com/ankane/strong_migrations) from 0.3.0 to 0.3.1.
- [Release notes](https://github.com/ankane/strong_migrations/releases)
- [Changelog](https://github.com/ankane/strong_migrations/blob/master/CHANGELOG.md)
- [Commits](https://github.com/ankane/strong_migrations/compare/v0.3.0...v0.3.1)

Signed-off-by: dependabot[bot] <support@dependabot.com>

* Improve README

* Update README.md

* Update README.md

* Update README.md

* Update README.md

* Update CONTRIBUTING.md

* Update CONTRIBUTING.md

* Update CONTRIBUTING.md

* Update CONTRIBUTING.md

Bumps [tzinfo-data](https://github.com/tzinfo/tzinfo-data) from 1.2018.5 to 1.2018.6.
- [Release notes](https://github.com/tzinfo/tzinfo-data/releases)
- [Commits](https://github.com/tzinfo/tzinfo-data/compare/v1.2018.5...v1.2018.6)

Signed-off-by: dependabot[bot] <support@dependabot.com>

* Use Ruby 2.5.2

* Specify 2.5.2p104 as RUBY VERSION

Heorku refers to RUBY VERSION in Gemfile.lock

* Use ruby-2.5.3

* Do not show "limited" visibility in default visibility preference

Fix regression from #8950

* Fix code style issue