Weight of wheel

[NaN]

Added optional mass, inertia parameter to wheel declaration in rev 2847.

Not a good idea because:
- masses an inertia may vary between steel-wheels/normal tyre and cart wheels/slick and rally car or a formula car,
- the result of weight, inertia computation is completely intransparent (can´t add masses in .car-file to totalweight) and
- the unsprung parts of suspension/brakes are unconsidered!

I'd avoid adjustments of wheel properties to get a certain handling. You would tune for the current implementation. And it has its own load of issues (like low inertia values).

I guess you've got some real-world wheel, unsprung parts mass and inertia values?