Passengers can grant upgrades to transport.
Desugaring a couple of ternary expressions which prevented OpenRA building on Mono 3.10 and certain versions of the 3.8 series due to a bug in Mono: https://bugzilla.xamarin.com/show_bug.cgi?id=23319
Merge pull request #6931 from Happy0/mono310_workaround

Workarounds for a bug in certain versions of Mono (3.10 and certain versions of 3.8) which stops OpenRA building
Merge pull request #6770 from atlimit8/PassengerProvidesUpgrade

Passengers can provide upgrade(s) to transport.
Actor properties consistency improved