Since the old keys used to be strings i started out by
json serializing the new keys with type, value, rev.

However storing serialized json in couch (json) does
not really make sense. So now we do not serialize but
instead have one json document. The lookup for a key of
type pgp may still return a string but for everything
that uses the new api it will return a hash with type
and revision.

This data structure is way easier to handle also on the
nickserver side.

We used to just ignore the key.
Also separated the code for handling key updates from other
user updates. This should eventually be moved to a different
route. Mixing the two makes the implementation really hard.

This simplifies returning the user while still working
on it a lot. Much cleaner than all these return user statements.

There's a lot more to refactor here. For example delegating methods
to user etc. ... but for now this should suffice. Don't want to
break this in a bugfix release.

fixes #8807

They used to be sorted by the code which was not helpful

fixes #8806
requires deploy of new design docs to the platform

Production instances are getting cluttered with invites from
test accounts. Instead of marking them as used we will now completely
remove them.

refers to #8804
refers to #8807\

make the rescue in account creation less broad

See merge request !15