These are the rest of the changes that have been accumulating in my dev
tree for v4 planetlab node support. Currently, we support both v3 and v4 NMs via a little wrapper, and we dist out different versions of the rootball depending on NM version. Also updated various parts of libplab to log success and failure from interactions with planetlab nodes to the db, and there are beginnings of support for that in plabmonitord.in.