Compatibility for mphbin/mphtxt in 2D and 3D

If you want to open a COMSOL Multiphysics geometry file in an earlier versions of COMSOL, you might need to set the COMSOL version using

model.geom(<tag>).export().setCompat(<ver>);

where <ver> is a string 3.5a, 4.0 (only 3D), 4.0a (only 3D), 4.2a, 4.3b, or 5.1.