Made SheetBuilder rely on global settings rather than global renderer.

Additionally exposed an InitializeSettings method on game to initialize the global settings so that other classes can set up all the secret dependencies on the global settings required.

OpenRA.Game/Game.cs

@@ -175,13 +175,18 @@ namespace OpenRA
 		public static Modifiers GetModifierKeys() { return modifiers; }
 		internal static void HandleModifierKeys(Modifiers mods) { modifiers = mods; }
 
+		public static void InitializeSettings(Arguments args)
+		{
+			Settings = new Settings(Platform.ResolvePath("^", "settings.yaml"), args);
+		}
+
 		internal static void Initialize(Arguments args)
 		{
 			Console.WriteLine("Platform is {0}", Platform.CurrentPlatform);
 
 			AppDomain.CurrentDomain.AssemblyResolve += GlobalFileSystem.ResolveAssembly;
 
-			Settings = new Settings(Platform.ResolvePath("^", "settings.yaml"), args);
+			InitializeSettings(args);
 
 			Log.AddChannel("perf", "perf.log");
 			Log.AddChannel("debug", "debug.log");