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

Since it is that :D

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

Fixes #817

add finnish translation

add finnish translation

add finnish translation

finnish translation

updated final translation

Still in progress. Should be done shortly

Fix typos and typography. Make vocabulary and grammar more uniform.