ether_ifdetach().
The former consolidates the operations of if_attach(), ng_ether_attach(),
and bpfattach(). The latter consolidates the corresponding detach operations.
Reviewed by: julian, freebsd-net
frame types. Currently it supports only IPX protocol and doesn't
affect existing functionality when not loaded.
Reviewed by: Ollivier Robert <roberto@keltia.freenix.fr>