Add logger(1) support for daemons that are logging to stdout/stderr (mostly from

Add logger(1) support for daemons that are logging to stdout/stderr (mostly from
the go ecosystem).
Properly handle failing daemon startup now that we have pipefail.

To take advantage of this new feature, just add foo_logger=facility to the
daemon rc.d(8) script or in rc.conf.local(8) or use rcctl:
rcctl set foo logger daemon.info

tweak for checking flags in rcctl(8) from martijn@
"this looks pretty good" deraadt@
ok sthen@