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

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

Allow custom files to be opened and allow sorting by timestamp.

While implementing a tool to import lastlog entries into utmpx, I
noticed lastlogin doesn't allow custom database files to be opened. Add
a -f switch to support this. Also, add -r and -t similar to ls(1),
ruptime(1), etc. where you can sort entries by timestamp and reverse
them. This allows you to spot active/idle users more easily.

Alphabetically sort the output of lastlogin(8).

According to the manpage, the entries have to be sorted by uid. This is
no longer possible, since our utmpx implementation is completely unaware
of user IDs. You can safely add entries for multiple users sharing the
same uid.

Make the output less random by sorting everything by name.

Remove stale references to utmp(5) and its corresponding filenames.

I removed utmp and its manpage, but not other manpages referring to it.

Mechanically kill hard sentence breaks.

The .Nm utility

mdoc(7) cosmetics.

Submitted by: sheldonh

Added the lastlogin utility.

Obtained from: NetBSD