construction yard -- make better range limit

Playtesting suggested we should increase the build radius from 10 to ~13/14.

Also changed pre-requisites so that "hq" pre-req is not "anyhq"
Nod gets mobile SAM launcher. MLRS & MCV speed

Nod now can use mobile SAM launcher. This is necessary because Orcas are powerful, esp. in large groups.
MLRS slowed down a bit, so it can't turn and run as swiftly.
MCV gets +1 speed since it will be moving more now. 
Orca, MLRS, mammoth balance stick

MLRS range reduced. People don't seem to like it's ultra-long range. Hopefully this is a good middle ground.
Orca range reduced -- there's some concern the orca is OP, especially against things designed to kill it (Bike, MSAM, ...). Reducing range will not nerf it but will allow vehicles to approach without getting instantly killed.
Mammoth missiles spread increased. Since mammoth is a top-tier unit, people think it shouldn't be easily killed and should be effective vs. everything. This should help a bit vs. infantry.
MLRS damage vs. wood reduced significantly, to slow down how fast they can destroy buildings.
MLRS damage vs. infantry slightly reduced. They are supposed to be good at killing incoming infantry groups, but they seem slightly too effective.
MCV no longer needs FIX to be built

MCV is more important now since buildings can only be built within its build range. If you need a repair bay first, it's too constrictive. This seems right. 
Building adjacent value increased

Since the MCV position limits where you can build, it seems like the adjacent value should be relaxed. 
Pchote, scott, mailaender and I were playtesting the new build radius. We played with a value of 5 and it was good.
changed pre-requisites from HQ to ANYHQ

Vehicles can still be built if communications center is destroyed, as long as player has either an advanced communications center or temple of nod.
infantry pre-req change "HQ" to "ANYHQ"

tier-2 infantry can still be built as long as you have advanced communications center or temple of nod. 
Gun & Guard tower detection range increased +1

The detection range for cloaked units for guard towers and guns is low (3). 
This is needed so that stealth tanks aren't too good at sneaking by everything. 
stealth tank range -1

Stealth tank range seems too high. It currently exceeds obelisk range. We won't be changing obelisk range until the FireDelay issue is fixed. https://github.com/OpenRA/OpenRA/issues/2710
Merge pull request #2912 from psydev/patch-1

construction yard limit; balance stick