Fix swapped accelerometer axes in 180 degree device rotation. Thanks to Mike3D. Closes #348.

Source/Android/src/org/libsdl/app/SDLActivity.java

@@ -809,8 +809,8 @@ class SDLSurface extends SurfaceView implements SurfaceHolder.Callback,
                     y = -event.values[0];
                     break;
                 case Surface.ROTATION_180:
-                    x = -event.values[1];
-                    y = -event.values[0];
+                    x = -event.values[0];
+                    y = -event.values[1];
                     break;
                 default:
                     x = event.values[0];