Converted "debug mode" option to simulate bringing the node down.  Seems
to work, still largely untested.
Fixed a bug that caused LT to incorrectly handle chunks of degree 1 that convert to blocks it has already seen.
In an effort to get to the root of Issue #27, I changed the program's response to connection reset by peer from barf
to ping everyone, then skip out of the forward thread early.  Hopefully
that will give us a little more information the next time it pops.