MOAITransformBase.getWorldRot() and .getWorldDir() are broken

`ZLMetaAffine2D/3D.GetRot()` pass their arguments to `atan2()` in the wrong order. Consequently, their results are always inverted and offset by 90°.

`ZLAffine3D.GetHeading()` should apparently return the vector (1, 0, 0), rotated by the rotation part of the transform. In what appears to be a copy-and-paste error from the same method in `ZLAffine2D`, the z coordinate is given the same value as the y coordinate, yielding strange results.