Reorganise RA-specific parts of Mods.RA a little more

OpenRA.Mods.RA/Traits/AcceptsSupplies.cs

@@ -0,0 +1,19 @@
+#region Copyright & License Information
+/*
+ * Copyright 2007-2014 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. For more information,
+ * see COPYING.
+ */
+#endregion
+
+using OpenRA.Traits;
+
+namespace OpenRA.Mods.RA.Traits
+{
+	[Desc("Tag trait for SupplyTruck: actors.")]
+	class AcceptsSuppliesInfo : TraitInfo<AcceptsSupplies> {}
+
+	class AcceptsSupplies {}
+}