Merge pull request #4 from changbl/working

Add inception ARP pre-config bash script
Finish ARP protocol redesign.
The controller stores three tables in itself
for IP-MAC address resolution and port look-up.
During forwarding, the controller will set
corresponding flows on each switch en route.

Add some comments in inception_arp_config.sh
Merge pull request #5 from powerist/working

Two tables finished
Cleanup code