Scenery Objects and stats

[mrSkortch]

Investigate feasibility of tracking scenery objects with regard to stats. Either in the form of counting the objects destroyed/hit by players or only counting under specific circumstances. For example check code for slmod.mapobj_destroyed and make a similar determination for the stats so world objects can be objectives.

Also need to check for issues related to weapon type failing to return or returning as the aircraft used by client is what killed the object, hence kamikaze kills. Likely similar to the static objects and kamikazes.