netfilter: remove messages print and boot/module load time

Several reasons for this:

* Several modules maintain internal version numbers, that they print at
  boot/module load time, that are not exposed to userspace, as a
  primitive mechanism to make revision number control from the earlier
  days of Netfilter.

* IPset shows the protocol version at boot/module load time, instead
  display this via module description, as Jozsef suggested.

* Remove copyright notice at boot/module load time in two spots, the
  Netfilter codebase is a collective development effort, if we would
  have to display copyrights for each contributor at boot/module load
  time for each extensions we have, we would probably fill up logs with
  lots of useless information - from a technical standpoint.

So let's be consistent and remove them all.

Acked-by: Florian Westphal <fw@strlen.de>
Acked-by: Jozsef Kadlecsik <kadlec@blackhole.kfki.hu>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>