Measure the TCP throughput of a TCP channel between two machines.

On one machine start "tcpspeed s" (the server).

On the other machine start "tcpspeed c <hostname>", where <hostname> is the
name of the machine running the server.

The client will received 20 MB of data from the server, and then calculate
and display the throughput.

29.7.2005: compiled with clib2 instead of newlib. This seems to fix the weird
results some people got.