Probe command:
 - add a new probe option "no-action". If set, an equipment does not make any action on the probe (like per rule routing or transformation).

PacketFilter :
 - handles interface negation (such as ! em0)
 - handles route-to(interface nodehost) filter-option

SimpleRouter:
 - An interface can be a "border". A border interface accepts all the incoming probe on it.

Fix:
- document the behavior of upercase/lowercase letter for tcp flags specification in the probe command.