newsyslog: Sync with FreeBSD.

newsyslog: Sync with FreeBSD.

-Don't consider non-existence of a PID file an error.
-Add -P flag which prevents further action if the pidfile is empty or
doesn't exist.
-Add a -S switch to override the default syslog pid file.
-Add support for creating the archived log filenames using a time-stamp
instead of the traditional simple counter.
-Add xz(1) support.
-Rewrite and simplify logfile compression code.
-Convert newsyslog to using queue(3) macros.
-Add file include processing.

Obtained-from: FreeBSD