Purpose: Look for the home directory of the user.
When called without optional 'subDir' argument, the path to the users home folder is returned. When 'subDir' is given, the path to the subfolder 'subDir' inside the home folder is returned - and the 'subDir' created inside that folder if neccessary.
History: 1/23/08 mpr configured it was about time to write this
3/7/08 mpr streamlined this
3/8/08 mk A bit more of streamlining - Don’t write the
PsychPrefsfolder.m file anymore.
4/28/08 mk Made compatible with Octave, added ‘subDir’
2/06/09 mk Derived from PsychtoolboxConfigDir().