Move weapon/turret definitions out of AttackBase.

Weapons are now defined with the Armament trait
and turret parameters live in Turreted.
This has the side effect of allowing any number
and distribution of weapons and turrets.

OpenRA.Mods.RA/Render/WithRotor.cs

@@ -30,9 +30,10 @@ namespace OpenRA.Mods.RA.Render
 
 			rotorAnim = new Animation(rs.GetImage(self));
 			rotorAnim.PlayRepeating("rotor");
+			var turret = new Turret(info.Offset);
 			rs.anims.Add(info.Id, new AnimationWithOffset(
 				rotorAnim,
-				() => Combat.GetTurretPosition( self, facing, new Turret(info.Offset)).ToFloat2(),
+				() => turret.PxPosition(self, facing).ToFloat2(),
 				null ) { ZOffset = 1 } );
 		}