CNC test changes

CHANGELOG: Balance updates for psydev's CNC balance test, v0.1

Purpose of changes:
Right now CNC is a bit too static due to overpowered base defenses, which requires large armies to attack with once defenses are up. Currently, some units are not useable enough, and some units are over-used. I tried to make each unit have a purpose or specific strength, but also have a weakness. For GDI, the mammoth tank is rather OP, while the Orca is really weak. It is better that a unit has a counter than to nerf it into oblivion; I think as long as there are strong air defenses in existence, Orca will not be OP (many AA units got upgrades some time ago).
In general, towers have been OP.  Artillery has been weak at hurting those towers because they don't do much damage against them, and are inaccurate.
For Nod, recon bike raids have been shut down pretty effectively by guard towers. Now they can stand a chance to destroy guard towers and buildings in small groups; though they do not out-range the towers.

Main Changes:
Nuke fixed (was broken and weak)
All towers have had their range reduced to 7.
All anti-air buildings had their range reduced to 8.
Guard tower damage vs. light vehicles decreased from 100% to 50%
Recon bike damage vs. wood increased from 50% -> 75%
Recon bike does less damage vs. infantry (65% -> 35%)
Nod Artillery does much more damage vs. heavy armor; more vs. wood & light vehicles; and slightly more vs. infantry
Mammoth Tank HP reduced 900 -> 800
Orca reload time reduced from 24 seconds to 12 sec. ROF slightly increased.
Orca damage vs. Heavy armor increased from 50% -> 75%
Orca air-to-air missiles do less damage than air-to-ground, to make fighting vs. Apaches roughly even
Advanced Guard tower now fires a SAM missile at air units, but a different rocket at ground units.
Adv. Guard Tower damage vs. ground units: more spread for explosion, more damage vs. infantry (25% -> 50%), a bit less damage vs. vehicles/tanks.
APC gets slightly slower firing rate, but now does more damage vs. heavy armor.
Flame Tank gets heavy armor; does more damage vs. light vehicles
Air Strikes can destroy guard towers and turrets again (and silos) but nothing else.
Airstrike does more damage vs. heavy armor.
Sniper can no longer fire at vehicles or buildings
MLRS does a bit more damage vs. wood and infantry
Light Tank does more damage vs. light vehicles
A-10 is no longer targetable, since units would start chasing them after airstrikes until they left the map
Mobile SAM does a bit more damage

Miscellaneous:
Transport helicopter lands a bit faster now (rotation speed increased)
Tiberium does a bit more damage than before (still not enough to kill usually)
Infantry more likely to walk through tiberium now
Nod Recon Bike slightly slower; rotation speed faster
Chem warrior fires less often but for more damage
Refinery holds slightly more ore; silos reduced in price
Infantry walk at 90% speed on clear terrain instead of 100% (this was the old setting)
Apache rotates faster, allowing it to point its guns more quickly at a new target. I think this makes it a bit more even against Orca in air-to-air situations.
Turret now does 100% damage vs. light armor (equalized with heavy armor)
Chem warrior speed in tiberium is the same as on open terrain

Changes that are uncertain, that might not be kept:
Hum-vee slightly slower; HP increased a bit
Flamethrower does more damage vs. light vehicles, and slightly more vs. infantry
Mobile SAM range reduced from 10 -> 9
MLRS spread increased from 15 -> 16