Purpose: Look for a folder for storing Psychtoolbox preferences; create if
When called without optional 'subDir' argument, the path to the root configuration folder is returned (and the folder optionally created if it doesn't exist yet). When 'subDir' is given, the path to the subfolder 'subDir' inside the root configuration folder is returned - and the 'subDir' created inside that folder if neccessary. Subfolders are useful to group related configuration data, e.g., all settings for DAQ toolbox, all display calibration settings, etc.
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’
6/14/09 mk Remove Octave code -> Not needed anymore.
4/10/17 mk Some cleanup and error reporting improvements.