branches: 1.1.2;
update to bluetooth device attachment:

remove pseudo-device btdev(4) and inherent limitations

add bthub(4) which autoconfigures at bluetooth controllers as they
are enabled. bluetooth devices now attach here.

btdevctl(8) and its cache is updated to handle new semantics

etc/rc.d/btdevctl is updated to configure devices from a list
in /etc/bluetooth/btdevctl.conf