netfilter: ipset: hash:ip,port set type support

The module implements the hash:ip,port type support in four flavours:
for IPv4 and IPv6, both without and with timeout support. The elements
are two dimensional: IPv4/IPv6 address and protocol/port pairs. The port
is interpeted for TCP, UPD, ICMP and ICMPv6 (at the latters as type/code
of course).

Signed-off-by: Jozsef Kadlecsik <kadlec@blackhole.kfki.hu>
Signed-off-by: Patrick McHardy <kaber@trash.net>