Refactor footprint cell lookups and move them to Building

Removing FootprintUtils happens in the next commit for better
reviewability.

OpenRA.Mods.Common/Lint/CheckBuildingFootprint.cs

@@ -1,36 +0,0 @@
-#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;
-using System.Linq;
-using OpenRA.Mods.Common.Traits;
-using OpenRA.Traits;
-
-namespace OpenRA.Mods.Common.Lint
-{
-	class CheckBuildingFootprint : ILintRulesPass
-	{
-		public void Run(Action<string> emitError, Action<string> emitWarning, Ruleset rules)
-		{
-			foreach (var actorInfo in rules.Actors)
-			{
-				var building = actorInfo.Value.TraitInfoOrDefault<BuildingInfo>();
-				if (building == null)
-					continue;
-
-				var footprint = building.Footprint.Where(x => !char.IsWhiteSpace(x)).ToArray();
-				var dimension = building.Dimensions;
-				if (footprint.Length != dimension.X * dimension.Y)
-					emitError("Invalid building footprint/dimension for " + actorInfo.Key);
-			}
-		}
-	}
-}