Merge remote-tracking branch 'origin/develop' into shigusegubu

* origin/develop: (55 commits)
  AP UserView: Refactor banner / avatar display code, add test.
  Test for MastoAPI /api/v1/instance response structure (formatting fix).
  Test for MastoAPI /api/v1/instance response structure.
  Credo is upset about me not remembering the alphabet
  Fix formatting
  Remove ActivityRepresenter
  Mastodon 2.7.2 instance attributes (registrations, languages).
  Increment replies_count on replies (MastoAPI)
  Comments split.
  Mastodon-based auth error messages. Defaulted User#auth_active?/1 to `true`.
  Try sending an empty map
  Attempt to fix incorrect federation of default instance avatars
  Add an id index to notifications
  fix up missing announcements with preloads
  Serve non-public activities in /api/v1/favourites
  add overriding truncated_namespace condition for truncating paths for digital ocean
  mrf/keyword_policy.ex: Fix when summary == nil, do not whitelist content == nil
  tests: fix up activity collision test
  activity: use left join instead of inner join when fetching activities that may or may not have a child object
  user: use preloads when deleting accounts
  ...

config/config.exs

@@ -173,7 +173,8 @@ config :pleroma, :instance,
   no_attachment_links: false,
   welcome_user_nickname: nil,
   welcome_message: nil,
-  max_report_comment_size: 1000
+  max_report_comment_size: 1000,
+  safe_dm_mentions: false
 
 config :pleroma, :markup,
   # XXX - unfortunately, inline images must be enabled by default right now, because