* Naive approached to timeline filtering

* Convert allowed_languages into a db column

* Allow users to choose languages to see statuses in

* Style list items as two columns

* Add a hint to explain language filtering preference

This reverts commit 5135d609b7.

* Add rough outline of coverage needed for public timeline

* Specs for visibility, replies, boosts

* Specs for silenced account

* Specs for local_only option

* Specs for blocks and mutes

* Add tentative spec around including other silenced account statuses

* Add with_public_visibility scope

* Add simple coverage for tag_timeline

* Tag timeline includes replies

* Replace tag.statuses with a tagged_with scope in tag timeline method

* Use with_public_visibility in tag timeline

* Extract common scope between public and tag timelines to method

* Extract local domain check to local_only scope

* Extract local_only check to starting scope method

* Move list of excluded from timeline account ids to account model

* Simplify excluded accounts list on account model

* Only join accounts when needed

* Rename method for account specific filtering

* Extract method for account exclusions

* Fix bug where silenced accounts were not including statuses from other silenced accounts

* DRY up filter application from account or no account

* timeline_scope can be private

* Add spec showing that account can find its excluded accounts ids

* Add spec which fails if local_only does not have a left outer join

* rubocop

Implement the two pending specs on `Status`: `reblogs_count` and
`favourites_count`.

Checking reblog vs original status was happening in multiple places
across the app. For views, this logic was encapsulated in a helper
method named `proper_status` but in the other layers of the app, the
logic was duplicated.

Because the logic is used at all layers of the app, we extracted it into
a `Status#proper` method on the model and changed all uses of the logic
to use this method. There is now a single source of truth for this
condition.

We added test coverage to untested methods that got refactored.

and atom feed generation to some extent, as well as the way mentions are
stored

relations on Status#mentions