nat: allow ACCEPT-target to explicitely disable NAT

Signed-off-by: Steven Barth <steven@midlink.org>
snats: fix missing print in reload-path

Signed-off-by: Steven Barth <steven@midlink.org>
snat: ICMP can be port-natted as well

Signed-off-by: Steven Barth <steven@midlink.org>
Fix building with newer toolchains

Signed-off-by: Steven Barth <steven@midlink.org>
snat: add support for connlimiting port-range SNAT

Signed-off-by: Steven Barth <steven@midlink.org>
Add support for device and direction parameters

Signed-off-by: Steven Barth <steven@midlink.org>
Add support for netifd-generated rules

Signed-off-by: Steven Barth <steven@midlink.org>