[WheelBase, WheelItemBase] Turned WheelItemDataType into a Lua type, made WheelBase:GetSelectedType() return the enum instead of a number.

src/WheelItemBase.h

@@ -19,7 +19,9 @@ enum WheelItemDataType
 	WheelItemDataType_Portal,	/**< The portal section on the Wheel. */
 	WheelItemDataType_Course,	/**< A Course on the Wheel. */
 	WheelItemDataType_Sort,		/**< A generic sorting item on the Wheel. */
-	WheelItemDataType_Custom	/**< A custom item on the Wheel. */
+	WheelItemDataType_Custom,	/**< A custom item on the Wheel. */
+	NUM_WheelItemDataType,
+	WheelItemDataType_Invalid
 };
 LuaDeclareType( WheelItemDataType );