tanks get increased spread, 3 -> 6

Tanks get chewed up pretty good by bazookas, and dont do much damage to infantry. This will help a bit to hurt infantry that are clumped up in the same cell.
increase turret strenght vs. vehicles a bit

gun tower should dispatch light vehicles as fast as the heavy.
turret got little buff vs. tanks since it's much weaker than gun.
tanks get buff vs. light armor

Tanks are a little under-performing vs vehicles. They should be able to dish out damage closer to as fast as light vehicles do to each other.
added stealth trike to show up in crates
Merge pull request #3101 from psydev/patch-1

d2k-tanks get increased spread, 3 -> 6