GUI: do not allow ":" in group name

- Do not allow ":" to be part of group.shortName
  (still can be part of group.name as names separator).
Merge pull request #126 from zlamalp/group

GUI: do not allow ":" in group name
GUI: display error ID in report box header

- Display error ID in heading of report box sice
  some users sends screenshot of an error
  instead of using report widget itself.
Merge pull request #127 from zlamalp/bug

GUI: display error ID in report box header