Improvement for usage on the field: Show if flight is complete or not

[niggli]

Possible idea: mark line red if flight is incomplete (for example no landing time towplane yet), yellow if complete but not landed yet (no landing time), no color if everything complete.

problem: OLC imported flights must be treated differently because no towplane data is needed

[niggli]

Ich werde bei diesem und anderen GUI Issues weiterfahren nach ein paar Tagen Pause..

[niggli]

Based on current experience with different users, this feature is not really needed because it is easily visible in the table if a flight misses something.