A temporary directory is now created for ModelFree4 output.
This directory is only created and the function for deleting it still needs to be added.
This follows the proposal of Edward d'Auvergne at:
https://mail.gna.org/public/relax-devel/2008-07/msg00038.html (message ID:
7f080ed10807290219m18601df6nf2df7e91848a9680@...).
