Start with grouped families in gcylc.

Also removes non-first-parent headings in family-grouped dot view.
Some code reuse.
Merge pull request #468 from hjoliver/gcylc-default-to-grouped

Start with grouped families in gcylc.
Gave get-task-status some command help.
Job poll and kill for pbs job submission.
No need to dump stderr from job poll commands.

Will be useful if errors occur, obviously.
Merge branch 'master' into job-poll-and-kill-etc
Commented out a debug print.
Merge branch 'master' into job-poll-and-kill-etc
gcylc right-click menu: poll and kill item names.
Fix for ssh messaging on this branch.

Was broken by merge from master last night.