this is not used anymore:
* not logged in users are redirected to the login page
* logged in users see the normal 404 page

updated_at is displayed in the frontend and should only be updated when
another notification_actor gets added

Also improved the sql-queries: update directly and not select first and
update then.

* move presenters back to controllers, this is view-logic
* use PostService in CommentService
* remove iframe route, this is not used anymore
* id/guid limit at 16 chars, hex(8) is 16 chars long

* move parameter normalization back to controller, because this is
  frontend-specific.
* if the StatusMessage is public, save also public photos

fix pod table migration if someone deleted a user (owner) manually

[WIP] Convert some cukes to rspec

already tested in spec/lib/evil_query_spec.rb

Cleanup aspect visibilities

Improve pod check

Rewrite mentions input using typeahead.js

* use port for check
* respect entries in /etc/hosts
* test /.well-known/host-meta
* don't allow redirects to other domains

* add port to pods
* remove url from person and link people with pod-table

* remove all for public posts
* remove all for deleted posts

Regression during from e596b1d2

also added a migration model