Lots of stuff added

Continuation of file transfer
Finished file transfer
Merge pull request #6 from chanpod/chauncey

Chauncey
Got 'dumb' GBN working

Still need to ACKNAK, and deal with dropped/corrupted packets
Think I got GBN mostly working, somehow. Need gremlin function to test full functionality

Also, I think it currently sends in chunks. That is, it waits for all 16
ACKS before sending the next 16 packets. It currently isn't a "sliding
window". Or maybe it is, I dunno
Merge pull request #7 from ProjFoo/skipper

Skipper