Setting of locale in controller extracted to Localized concern,
the doorkeeper authorized applications controller moved under
custom namespace with inclusion of Localized, which resolves the
"it sometimes appears in a different random language" bug

* Rewrite Atom generation from stream entries to use Ox instead of Nokogiri::Builder

StreamEntry is now limited to only statuses, which allows some optimization. Removed
extra queries on AccountsController#show. AtomSerializer instead of AtomBuilderHelper
used in AccountsController#show, StreamEntriesController#show, StreamEntryRenderer
and PubSubHubbub::DistributionWorker

PubSubHubbub::DistributionWorker moves n+1 DomainBlock query to PubSubHubbub::DeliveryWorker
instead.

All Salmon slaps that aren't based on StreamEntry still use AtomBuilderHelper and Nokogiri

* All Salmon slaps now use Ox instead of Nokogiri. No touch from status on account

Reduced by running through `guetzli` image optimizer.

slightly optimized FanOutOnWriteService again

Updated some translations after seeing them in service. Should be better now

We're going to want these nice helper methods, lets share them with a parent class that matches Rails 5 practices (application level abstraction)

By pushing this into a worker we can reduce the amount of time the feed manager using workers eat up a connection

This stores the @username@instance you provide in your session and
reuses it the next time you remote follow someone from this instance.

This adds the ability to filter user signup with a whitelist
instead of or in addition to a blacklist.

Fixes #817

make regeneration worker unique, (only schedule/execute once at a time)

do not re-create a dynamic class on each feed push call, make sure redis-rb uses hiredis