net/haproxy: enable logging

fixes for net/haproxy

net/haproxy: add HAProxy load balancer to plugins

PR: https://forum.opnsense.org/index.php?topic=1332

Switch to an easier way of doing service launching, solving the
early boot issue for ports-based kernel modules by introducing
the rc.syshook script.

That's already a lot better, but will need further refinement.  :)

o add a LOCALBASE override
o split off plist from install
o copy known `+' script files