slowly teasing the view+controller out of the model classes.

actually doesn't work right now, but that will change.

git-svn-id: svn://svn.ijw.co.nz/svn/OpenRa@2050 993157c7-ee19-0410-b2c4-bb4e9862e678

OpenRa.Game/UiOverlay.cs

@@ -39,6 +39,8 @@ namespace OpenRa.Game
 				for (int j = 0; j < height; j++)
 					spriteRenderer.DrawSprite(blocked ? buildBlocked : buildOk,
 						24 * (position + new int2(i, j)) + game.viewport.Location, 0);
+
+			spriteRenderer.Flush();
 		}
 
 		bool blocked, hasOverlay;