Comment # 3 on bug 1201852 from Adam Majer

There is no support for other than manpages in libalternatives, so this is out
of scope. The only thing that can be done here is the manpage should be patched
to refer to `info mailutils mail` instead of just generic name.

IMHO, it's broken to refer to non-explicit names in the first place. Generic
names are substitutable but actual programs are not. manpage for mailutils mail
should refer to info mailutils mail. mailx manpage is much nicer.