The packetFactory is no longer part of the global environment

Instead every ARAClient has now its own PacketFactory.
This is a nessecarry preparation for the upcommung change, that the
packet factory will now the parameter for the maximum hop count (TTL)
which can vary between distinct clients
The packet factory does now hold the maxHopCount value itself
The message dispatcher does now use a packet factory to create the OMNeTPackets