List the desired non-free sections to use in NONFREE_COMPONENTS in
CONF.sh, default to "non-free non-free-firmware" by default until
things are all migrated.
+ Remove the old non-US stuff from it, it's not been needed in years.
+ Cope with .bz2 source files too.
+ Merged and simplified the old functionality from scansources.old
and scanpackages.old into the new script create_control.