Fixed the "You password will expire in 0 days. Would you like to

Fixed the "You password will expire in 0 days.  Would you like to
change it now?" message when you login to a Samba Controlled domain.

The fix is a hard coded 42 days from right now until you need to
change you pasword again time (see passdb/sampassdb.c:pwdb_smb_to_sam())

Also fixed getsmbfilepwent() so that it will read in the last password
change time correctly.

* Related to this lib/util_pwdb.c:StrnCaseCmp() returns 0 if the
strings match.  Chouldn't this be the pther way?  Oh well.  I
didn't change the return code as it was used in several
other cases (see lib/util_pwdb.c:pwdb_get_last_set_time())