REGISTRAR: check for similar users when auto-approving application

- If VO's initial application is set to auto-approve mode, then stop
  the process, when similar users are found and notify VO admin
  about the problem. Application can be then approved manually.

- Other types of application doesn't create new User, so we don't have
  to check for similar users.
GUI: updated RT reporting

- Pass also actor/extSource to ticket if user==null so we would
  know, who sent the error request.
- Fixed text before instance string.
Merge pull request #439 from zlamalp/rt

GUI: updated RT reporting
Merge pull request #431 from zlamalp/nonapprove

REGISTRAR: check for similar users when auto-approving application
REGISTRAR: catch other exceptions too when auto-approving

- When auto-approving application, catch also UserExtSourceNotExists
  and ExtSourceNotExists exceptions, since it means, that user is unknown
  and we can't allow to approve Group initial application.
GUI: added more available tag options to help

- Added more available tags when creating/editing notifications.
Merge pull request #440 from zlamalp/registrar

REGISTRAR: catch other exceptions too when auto-approving