Integrate the "edge" apps

[MurphyMc]

Back when I had time to work on POX, I wrote a couple "edge" example apps, where POX controls OVS instances which are tied together by tunnels over a non-OpenFlow network. This work then got continued by @garyachy. Unfortunately, I ran out of time to work on this stuff and it got basically abandoned.

I think it might be nice to bring these back from the dead. There are some instructions for running them in Mininet, but they're many years out of date now and I'm not in a position to fix them since I don't use Mininet anymore. If I remember right, this was tricky to get working at the time due to bugs in OVS or Linux tunneling, though I think I may have submitted patches? Maybe it "just works" now.

Here's the old code:

• Originals: https://github.com/MurphyMc/pox/tree/experimental/pox/edge
• More work which never got merged: https://github.com/garyachy/pox/tree/edge/pox/edge

And there's some info on the aggregator component here:

• https://haryachyy.wordpress.com/category/sdn/pox/