added units.ini (and campaignUnits.ini), and IniFile got support for load/merging multiple files.

- Rules can now handle map-specific rules changes
    - units.ini replaces {buildings,units,infantry}.txt (or will replace; sidebar still uses them)
    - Added support for loading map-placed units/structures - try scg11eb.ini
        - added FCOM

OpenRa.Game/Actor.cs

@@ -117,6 +117,10 @@ namespace OpenRa.Game
 				traits.Add(new Traits.RenderBuildingOre(this));
 				break;
 
+			case "fcom":
+				traits.Add( new Traits.Building( this ) );
+				traits.Add( new Traits.RenderBuilding( this ) );
+				break;
 			default:
 				throw new NotImplementedException( "Actor traits for " + name );
 			}