split out hardcoded editor tools into ITool impls

OpenRA.Editor/ITool.cs

@@ -0,0 +1,20 @@
+#region Copyright & License Information
+/*
+ * Copyright 2007-2010 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 LICENSE.
+ */
+#endregion
+
+using SGraphics = System.Drawing.Graphics;
+
+namespace OpenRA.Editor
+{
+	interface ITool
+	{
+		void Apply(Surface surface);
+		void Preview(Surface surface, SGraphics g);
+	}
+}