Replaced 'form xxxx import *' with 'from xxx import yyy, aaa....' in relax_gui.py.
This corresponds to the import_patch file attached to https://gna.org/task/?6847 by
Michael Bieri (https://gna.org/users/michaelbieri), in the zip file
https://gna.org/support/download.php?file_id=7726.
