fixed issue with renaming repos group together with changing parents with multiple nested trees
added regresion tests for such cases

fixes #762, LDAP and container created users are now activated based on
the registration settings in permissions

moved out password reset tasks from celery, it doesn't make any sense to keep them there, additionally they are broken
in when executing _(), and url() calls. This fixes issue #572

fixes issue #756 cleanup repos didn't properly compose paths of repos to be cleaned up.
- it just worked on repos on root filesystem

git hook handler shouldn't ever use cache instances
- moved cache invalidation into finally block so we invalidate at latest possible stage
- added scm_instance_no_cache property to get non cached scm instances always

reposcann should skip directories with starting with '.'
some code cleanup, moved all skipping to get_repos function

fixes for issue #731, update-repoinfo sometimes failed to update data when changesets
were initial commits

improved extraction of user from changeset when sending notification.
Fallback to repo owner if we cannot get the user