An icon is now displayed in the pending jobs when the cargo/PAX is assigned to a Work Order

WorkOrders:
- Added an option to force the crew to rest at the end of a leg

- Added hours format for ETE
- Cargo warning now displays correctly
Other changes:
- Added an option in the global settings to disable map tiles caching
- Added an option to replace the aircraft airframe
Aircraft maintenance: added maintenance end date estimation using current assigned mechanics