Replace Mix.env with Pleroma.Config.get(:env)

See merge request pleroma/pleroma!1254

Mix Tasks: Switch to Application.ensure_all_started instead of Mix.Task.run and ensure serve_endpoints is set to false

See merge request pleroma/pleroma!1255

Mix.Task.run and ensure serve_endpoints is set to false

In release environments there is no Mix.Task.run and serve_endpoints
must be set to true for the endpoints to start, so we need to ensure it
is set to false before starting Pleroma for executing a mix task.

Mix.env/0 is not availible in release environments such as distillery or
elixir's built-in releases.

Switch to manual Supervisor child specifications instead of Supervisor.Spec

See merge request pleroma/pleroma!1252

Fix search

Closes #960

See merge request pleroma/pleroma!1253

Supervisor.Spec is deprecated and causes warnings on Elixir master, see
https://hexdocs.pm/elixir/Supervisor.Spec.html

[#943] Make the unauthenticated users limitation optional

See merge request pleroma/pleroma!1251

Bugfix/377 stuck follow request

Closes #377

See merge request pleroma/pleroma!1250

[#943] Contain search for unauthenticated users

See merge request pleroma/pleroma!1220

User: Don't error out when following a user that's already followed.

See merge request pleroma/pleroma!1249

OAuth consumer: tests fix, comments, Keycloak config notes

See merge request pleroma/pleroma!1248

This leads to a few situations where it is impossible to follow a user.

Explicit addressing

See merge request !1239

Mix: Swallow git error messages during version number handling.

See merge request pleroma/pleroma!1247

Participations: Filter out participations without activities.

Closes #956 and #953

See merge request pleroma/pleroma!1246

Otherwise sometimes a 'fatal' message will be printed, confusing users.

[#941] add option skip_thread_containment

See merge request pleroma/pleroma!1237