Removes various hardcoded properties from specific game-type objects.

[CCHyper]

Closes #554

This pull request removes various hardcoded properties of specific game-type objects. It's quite possible these properties were hardcoded during one of the original patch cycles by a programmer who did not have the access or time to modify the rules file.

The following hardcoded properties are now removed;

• GuardRange=5 and Cost=250 from TechnoTypes GAFSDF, GAWALL, and NAWALL.
• Explodes=yes from TechnoType E2.
• BaseNormal=no from BuildingTypes NAFNCE and NAPOST.
• ProneDamage=0.3 and Verses=0.4, 0.85, 0.68, 0.35, 0.35 from WarheadType ARTYHE.
• ROF=150 and Damage=115 from WeaponType 155mm.
• Power=17 from TiberiumType Vinifera.