evaluate: improve rule management checks

evaluate: improve rule management checks

Improve checks (and error reporting) for basic rule management operations.
This includes a fix for netfilter bug #965.

Netfilter bug: http://bugzilla.netfilter.org/show_bug.cgi?id=965
Reported-by: Jesper Sander Lindgren <sander.contrib@gmail.com>
Suggested-by: Pablo Neira Ayuso <pablo@netfilter.org>
Signed-off-by: Arturo Borrero Gonzalez <arturo.borrero.glez@gmail.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>