This directory contains the implementation of IP session tracking and
processing functions.  When the network protocol for a flow is determined
to be IP the base Stream preprocessor will delegate handling of the packets
on that flow to this module.

The StreamIp class is implemented as a subclass of Inspector and provides
functions for loading stream IP configuration and packet evaluation.  The
packet eval method is not used as the base Stream Inspector delegates
packets directly to the IP session packet processing method.

The module ip_ha.cc (and ip_ha.h) implements the per-protocol hooks into
the stream logic for HA.  IpHAManager is a static class that interfaces
to a per-packet thread instance of the class IpHA.  IpHA is sub-class
of ProtocolHA, declared in the stream/base area.  Thus each protocol
within 'stream' can have specific HA logic and interfaces.

IpHAManager::process_deletion() is called when an IP stream is being 
destroyed and indicates to the stream & flow HA logic that a flow
deletion HA message needs to be emitted for the flow in question.
Ip streams are closed due to timeout or pruning actions which lead
to the invocation of process_deletion().

IpHA::create_session() is called from the stream & flow HA logic and
handles the creation of new flow upon receiving an HA update message.
