Add ImpactOrientation to WarheadArgs

Allows to pass the horizontal facing/yaw
and vertical angle/pitch of the carrier
projectile to warheads for further use.

Add ImpactPosition to WarheadArgs

InflictDamage doesn't pass the impact pos
directly, and the very point of WarheadArgs
is to avoid adding more and more arguments
to the warhead methods.

OpenRA.Game/GameRules/WeaponInfo.cs

@@ -38,6 +38,8 @@ namespace OpenRA.GameRules
 		public WeaponInfo Weapon;
 		public int[] DamageModifiers = { };
 		public WPos? Source;
+		public WRot ImpactOrientation;
+		public WPos ImpactPosition;
 		public Actor SourceActor;
 		public Target WeaponTarget;
 
@@ -45,6 +47,7 @@ namespace OpenRA.GameRules
 		{
 			Weapon = args.Weapon;
 			DamageModifiers = args.DamageModifiers;
+			ImpactPosition = args.PassiveTarget;
 			Source = args.Source;
 			SourceActor = args.SourceActor;
 			WeaponTarget = args.GuidedTarget;