MFC r356601-r356602: inetd fixes for WITHOUT_* knobs

r356601:
inetd: free WITHOUT_INET6_SUPPORT build of warnings

If inetd is compiled without inet6 support, we need to error out on
rpc+inet6 services rather than attempting to call into rpc bits with an
uninitialized netid.

v4bind is only used with INET6 support, so move it under the proper #ifdefs
with v6bind.

Reported by: Pavel Timofeev <timp87 gmail com>

r356602:
inetd: two more nits

Use COPYRIGHT for copyright to simply either embed it via .ident or have
it properly marked unused

Move an ipsec reference to IPSEC