Sites: Mitigate capture zone site objects falling under the terrain

[dijksterhuis]

Should be a case of setting the object z-co-ordinates to be > 0 and then setting up vector.

Static weapons have historically seemed to be a special case. When mortars are spawned on rice paddy terrain objects the mortars always seem to fall through the world. I believe this also happens for other static weapons too, but am not 100% on that.

There is the a paradigm fallthrough world checker system. from memory, I believe it checks objects once and then stops checking if they have been fixed to not fall through the world.