bug#12083: bug in groups command -- doesn't quote usage of group-separator in groupnames

[Linda Walsh]

the 'groups' only prints out a bunch of words, but it doesn't tell me which
of those are groups and which of those are not groups.

It uses unquoted , space separated group name -- which has been known to be
problematic for years (cf. find's -print0, or xargs -0, et al.).

If this was only a default, and it could optionally print them 1/line or
a backslash before non-separator spaces in groupnames, or even with a
null like find, it might be workable, but the default, as it is 100% likely
to not print out Windows groupnames that it might be serving.

Even if it could use a TAB separator, that would still count as white space,
but be 99% less likely (maybe 100%) to conflict with existing group names.

Fixable?  As it doesn't follow standards now, if one uses a space as a
group separator, as what is listed, is incorrect (i.e. interpreting the list
as a space separated group list will result in faulty results).

Thanks,
:-)