Some functions changed return type from python2 to python3

TODO: not everything is tested, a full review is needed + run is needed

Nowadays we only keep one product depending on its name, we do not care
about double even if id is not the same.

As id can contains important and different information even if products
names are the same, we should keep all those product groupes byb name
and pass them all to modules.

Modules will only keep products they can handle

python modernize.py --no-six -f libmodernize.fixes.fix_print -w

With manual fixes as the import was put always on top.

refs #803

refs #806

This is recommended by Debian.
closes #618

Florent authored Nov 12, 2012 and Romain Bignon committed Nov 12, 2012

Close #934