Merge branch 'ct_rt_syntax_06'

inet family (and others, e.g. bridge) lack context to figure out the
layer 3 address type.

examples:
ct original saddr $addr
rt nexthop $addr

We can't use $addr, because it might be a set reference, e.g.

ct original saddr @whitelist

currently implemented workaround is to use 'meta nfproto' to provide the
l3 context, e.g.

meta nfproto ip rt nexthop 10.2.3.4

i.e. users need to fill dependency manually.

Pablo suggested to instead specify ip saddr, ip6 saddr:

ct original ip saddr $address

and then let nft handle the dependency injection, these changes do this.
Old syntax is preserved.

Signed-off-by: Florian Westphal <fw@strlen.de>
Acked-by: Pablo Neira Ayuso <pablo@netfilter.org>