Fixed flipX bug.

spine-as3/spine-as3/src/spine/Bone.as

@@ -40,7 +40,7 @@ public class Bone {
 			_worldRotation = _parent._worldRotation + rotation;
 		} else {
 			_worldX = flipX ? -x : x;
-			_worldY = flipX ? -y : y;
+			_worldY = flipY ? -y : y;
 			_worldScaleX = scaleX;
 			_worldScaleY = scaleY;
 			_worldRotation = rotation;