* add haml_lint to Gemfile

* add .haml-lint.yml

* fix warnings of haml_lint

Like it's already done when you click on an application from a toot, it's opening in a new window.
0254ee9795/app/views/stream_entries/_detailed_status.html.haml (L41)

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

to the API