Make behavior of getsockname(2) (and maybe getpeername(2)) as the same as
NetBSD 6.1_STABLE and other operating system (OS X 10.9.5).

* sa_len of sockaddr_un strucrure is always set to sizeof(sun_path).
* pathname stored in sun_path is alwasys '\0' terminated (except length
  of sun_path is sizeof(sun_path)?).

Should be fix PR kern/49247, runtime problem of lmtp service of dovecot2 on
NetBSD current and NetBSD 7.0_BETA.
The tzoff argument is in minutes (behind/west of UTC), not seconds.

While here, also say that time = NULL and tzoff = NULL are independent.
The code doesn't yet implement that, but it will soon.
When tests fail, print all args, notjust the date string.
2013-07-09 was in British Summer TIme, so use tzoff=-60, not 0.
Improved handling of local times.

* A magic value USE_LOCAL_TIME (defined as 99999) may be passed as the
  Timezone to Convert(), instructing it to use mktime() to work
  in the local time zone, instead of using mktime_z to work in UTC
  (and then adding the specified timezone offset).
* Some old code is removed now that there's no need to find the local
  timezone offset.
* Allow either one or both of the now and zone arguments to
  parsedate() to be NULL, treating them independently.  Previously,
  if either one was NULL, the other was ignored.
* If the zone argument is specified, then the current date is calculated
  in the specified zone, not in local time.

Also add some disabled debug code.

This should fix PR lib/47916.