Variant of utime(2) with struct timespec (with ns precision)
instead of time_t values; also allows for tv_nsec members
the values UTIME_NOW (force update to current time) or
UTIME_OMIT (allow to set either atim or mtim independently.)
Provides a superset of utimes(2), futimes(2), lutimes(2),
and futimens(2).
Provides the same subset of utimensat(2) as does NetBSD 6.
Also import utimens() and lutimeNS() from NetBSD-current.
