cylc gpanel: add traceback handling
gcylc: add uncaught exception dialog
Merge branch 'gpanel.fix-idle-start' into gcylc.gui-exception-dialog
gcylc: add cylc gpanel error report
Added a new submit-retry task state.

Functionally equivalent to execution retry, but useful nonetheless.
Merge branch 'master' into submit-retry-task-state
gcylc: modify error report text
Merge pull request #618 from benfitzpatrick/gcylc.gui-exception-dialog

Exception handling for cylc GUIs
Merge pull request #619 from hjoliver/submit-retry-task-state

Added a new submit-retry task state.
Fix gcontrol tree check boxes.
Move db status updates to set_status method and ignore redundant operations.
Code tidy.
Merge pull request #624 from arjclark/fix-gcontrol-checkbox

Fix gcontrol tree check boxes.
Merge pull request #625 from arjclark/check-redundant-state-updates

Check redundant state updates