Copy head (r256279) to stable/10 as part of the 10.0-RELEASE cycle.

Approved by: re (implicit)
Sponsored by: The FreeBSD Foundation

Rework all non-contributed files that use `struct timezone'.

This structure is not part of POSIX. According to POSIX, gettimeofday()
has the following prototype:

int gettimeofday(struct timeval *restrict tp, void *restrict tzp);

Also, POSIX states that gettimeofday() shall return 0 (as long as tzp is
not used). Remove dead error handling code. Also use NULL for a
nul-pointer instead of integer 0.

While there, change all pieces of code that only use tv_sec to use
time(3), as this provides less overhead.

Merge r114010 of head/usr.bin/login/login.c into PicoBSD's login.c:

Correct the login.conf variable name used for obtaining the login prompt.

PR: conf/44717 (indirectly)
Spotted by: gcooper
MFC after: 1 week

Correct two error messages to match the failure they are reporting.

MFC after: 1 week

a minimal set of changes to adapt to the utmp->utmpx changes.
lastlog still not implemented, i am hoping that Ed or someone
has some idea on how to fix this, but it is really not important.

NI_WITHSCOPEID cleanup. Neither RFC 2553 nor RFC 3493 defines
NI_WITHSCOPEID, and our getaddrinfo(3) does nothing special
for it, now.

de-__P()

Align for const poisoning in -lutil.

Synch with login/login.c,v 1.81: Switch to OpenPAM.

Fix a typo (missing "; at the end of a string)

Add customised version of login for picobsd images on -CURRENT.
This version is basically the same one as login.c 1.67, and does
not require the use of PAM.