how to use nock
---------------

make builds a client (clt) and a server (srv)

srv with no arguments starts the server on the current
host.

clt with no arguments prints available commands.

e.g.,

clt -h HOST -r 10 -t

(where HOST is the name of a machine running srv)
will run 10 throughput experiments sending 1 MB (see
option -n) in 1KB blocks (-z), reporting rates observed
by clt and srv.