infantry speed increased from 90% to 100%.

During playtesting it seemed like having infantry go at full speed on clear terrain was a good addition.
If it seems inappropriate for some infantry, can change it individually later for some units that might be too fast (e.g. flamethrowers and grenadiers, who travel at speed=5).
mammoth turret rotation 2 -> 3, matching tank rot.

A good idea to make mammoth able to rotate to face air units it wants to hit, faster. 
APC gun does slightly more dmg; slower ROF

APC gun does 30 damage, so it can kill orca in 3 shots.
ROF lowered to compensate. 
orca, apache require ANYHQ instead of HQ

allows units unlocked by HQ to stay available as long as you have either advanced comm. center or temple of nod.
Merge pull request #2948 from psydev/patch-1

balance stick - infantry, mammoth