Show marked-up estimated or true finish time in text view.
Returned some date-time calculations to the daemon.
Added an icon for unknown state.
Back compat for gcylc graph view.
Fix for gcylc dot-size.
Tidy previous commits.
Merge pull request #1123 from hjoliver/1121-gcylc-tfinish

Show marked-up estimated or true finish time in text view.