add support for compressed packages (zip); strip unnecessary SharpZipLib dll. req reference to WindowsBase for System.IO.Packaging support (apparently Mono has it)

OpenRA.Mods.RA/PaletteFromRGBA.cs

@@ -40,4 +40,18 @@ namespace OpenRA.Mods.RA
 			}
 		}
 	}
+
+	class SingleColorRemap : IPaletteRemap
+	{
+		Color c;
+		public SingleColorRemap(Color c)
+		{
+			this.c = c;
+		}
+
+		public Color GetRemappedColor(Color original, int index)
+		{
+			return original.A > 0 ? c : original;
+		}
+	}
 }