Rename HeliReturn

Rename HeliReturn to HeliReturnToBase to keep somewhat with the convention established for Plane- against Heli- oriented traits.

OpenRA.Mods.Common/Activities/Air/HeliAttack.cs

@@ -67,7 +67,7 @@ namespace OpenRA.Mods.Common.Activities
 			// If all ammo pools are depleted and none reload automatically, return to helipad to reload and then move to next activity
 			// TODO: This should check whether there is ammo left that is actually suitable for the target
 			if (ammoPools.All(x => !x.Info.SelfReloads && !x.HasAmmo()))
-				return Util.SequenceActivities(new HeliReturn(self), NextActivity);
+				return Util.SequenceActivities(new HeliReturnToBase(self), NextActivity);
 
 			var dist = target.CenterPosition - self.CenterPosition;
 

OpenRA.Mods.Common/Activities/Air/HeliReturnToBase.cs

@@ -15,11 +15,11 @@ using OpenRA.Traits;
 
 namespace OpenRA.Mods.Common.Activities
 {
-	public class HeliReturn : Activity
+	public class HeliReturnToBase : Activity
 	{
 		readonly Aircraft heli;
 
-		public HeliReturn(Actor self)
+		public HeliReturnToBase(Actor self)
 		{
 			heli = self.Trait<Aircraft>();
 		}