Also move "shareable hidden"-logic to AlsoCommented, because it is the
only one that needs it. And write some specs for mentioned and started
sharing notifications.

Fixes #6294

otherwise we have data-inconsistency if the user stops ignoring the
person.

fix #6857

also display message if the user has no invitations left and refactored
InvitationsController spec and remove unused message parameter

otherwise the counter goes into negative ;)

also  reset all negative counters

Fixes #5116

If you look at comment expand process with javascript debugger, you
will notice that at first comments get added to existing stream ("add"
event handler of model.comments gets launched because of model.comments.fetch).
Then the comment stream gets empty and then filled by the postRenderTemplate
handler.

This patch removes comments rerendering on the expansion. The fetching process is
changed so that older comments are added to the correct place, so the order
looks nice without rerendering. Thus, unnecessary job of rerendering is avoided.

The desktop frontend now treats the "name" parameter of mention as
a string to display unconditionally. But the Diaspora::Mentionable
renders mentions the different way: "name" is treated as a fallback
string which is rendered only if the person's name is unavailable.
This reflects on the mobile version ATM. This patch makes it behave
the same way as the current desktop version does.

Fixed:
* wrong url
* broken navigation
* broken design
after saving the user settings

Fixes #5847

only expose routes from devise that we actually use