Refactor supply traits to *Cash traits

Adding 'Type' and 'Stances' support as well.

OpenRA.Mods.Common/Traits/AcceptsDeliveredCash.cs

@@ -0,0 +1,33 @@
+#region Copyright & License Information
+/*
+ * Copyright 2007-2017 The OpenRA Developers (see AUTHORS)
+ * This file is part of OpenRA, which is free software. It is made
+ * available to you under the terms of the GNU General Public License
+ * as published by the Free Software Foundation, either version 3 of
+ * the License, or (at your option) any later version. For more
+ * information, see COPYING.
+ */
+#endregion
+
+using System.Collections.Generic;
+using OpenRA.Traits;
+
+namespace OpenRA.Mods.Common.Traits
+{
+	[Desc("Tag trait for actors with `DeliversCash`.")]
+	public class AcceptsDeliveredCashInfo : ITraitInfo
+	{
+		[Desc("Accepted `DeliversCash` types. Leave empty to accept all types.")]
+		public readonly HashSet<string> ValidTypes = new HashSet<string>();
+
+		[Desc("Stance the delivering actor needs to enter.")]
+		public readonly Stance ValidStances = Stance.Ally;
+
+		public object Create(ActorInitializer init) { return new AcceptsDeliveredCash(init.Self, this); }
+	}
+
+	public class AcceptsDeliveredCash
+	{
+		public AcceptsDeliveredCash(Actor self, AcceptsDeliveredCashInfo info) { }
+	}
+}