added the PermissionStack class and PostPermissionGateways 'namespace'
fixed minor bugs
major changes to the PermissionStack class. introduced single query system
added some basic frontend. linking left
finished linking. testing leftover
preliminary tests done. somewhat functional.
added a migrate management command and also added the files that actually
contain this branch's modification...
Fixed conflicts in mrge acces-rights and serch
Merging access-rights
Merge branch 'access-rights' into search
Merged access-rights, working fine