libnetfitler_queue improvements

Hi Patrick,

These are for 2.6.23 tree. The first patch might be better
to
go 2.6.22. Either one is fine with me.

BTW, I think we'd better to do nothing for
NFQNL_CFG_CMD_PF_[UN]BIND
commands and to register queue handlers at init()
automatically after
removing ip[6]_queue.

Because they are diffcult to use. Even if we apply the first
patch, a user
process can unregister a queue handler registered by other
process. And
there is no way to count the number of process to use the
handler (refcount
per handler doesn't help because process can issue
[un]binding command over
again and again).

-- Yasuyuki Kozakai

Subject is wrong. nfnetlink_queue not libnetfilter_queue.
Sorry.

-- Yasuyuki Kozakai