Do not let pw.conf(5) or -M option affect creation of basehome, e.g., /home.

Do not let pw.conf(5) or -M option affect creation of basehome, e.g., /home.
When the basehome does not exist, it creates all intermediate directories as
required, which is logically equivalent to mkdir(1) with -m and -p options.
However, it modifies all intermediate directories, not just the final home
directory unlike mkdir.  This problem was introduced in two revisions, i.e.,
r1.59 (SVN r167919) and r1.60 (SVN r168044).

MFC after:	1 month