[test] AbstractsCtrl: Test abstr. creation when conf. is closed

And user is a normal user
[ctrl] Abstract: Prevent abstr. creation when conf. is closed

It is still allowed for admins and conference owner
[ctrl] Abstracts: If conf is closed, InRevision is req. for updates

Only in the InRevision state we should allow updates to the body
of the abstracts.
Merge pull request #208 from gicmo/permFixes1

Fix abstract creation, update security when conference is closed

Thanks