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.Mods.Common/Util.cs

@@ -108,6 +108,15 @@ namespace OpenRA.Mods.Common
 			return WPos.Lerp(fromPos, toPos, 1, 2);
 		}
 
+		public static WAngle GetVerticalAngle(WPos source, WPos target)
+		{
+			var delta = target - source;
+			var horizontalDelta = delta.HorizontalLength;
+			var verticalVector = new WVec(-delta.Z, -horizontalDelta, 0);
+
+			return verticalVector.Yaw;
+		}
+
 		public static IEnumerable<T> Shuffle<T>(this IEnumerable<T> ts, MersenneTwister random)
 		{
 			// Fisher-Yates