[API] don't store ID tokens in DB

fix #6857

fix migration for invitation-cleanup

delete invitations-table (and constraints) before deleting the users

Add rake task to move jobs from any legacy queue to the default queue

Cleanup invitations

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

Fix charcounter position in publisher

Fixes #5116

Comments expansion refactoring

Adding bootstrap-markdown editor

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.

Add 'no posts yet' message to empty streams

Add role='alert' to alerts

Disable animations in poltergeist