Misc changes

* Use Pair instead of KeyValuePair
* double -> var
* Butcher XML comments
* Change WinState default to Undefined and use it instead of the new GameOutcome
* Other changes

OpenRA.Game/Widgets/LabelWidget.cs

@@ -58,7 +58,7 @@ namespace OpenRA.Widgets
 		{
 			SpriteFont font;
 			if (!Game.Renderer.Fonts.TryGetValue(Font, out font))
-				throw new ArgumentException("Request font '{0}' was not found.".F(Font));
+				throw new ArgumentException("Requested font '{0}' was not found.".F(Font));
 
 			var text = GetText();
 			if (text == null)