Changing Throughput test program to a Python based one.

* This change is need to prevent problems related to the TCP send buffer
being overflowed in the original Throughput app which resulted in the
greetingListener thread being blocked. Thus not detecting further
contats and not initiating the Throughput test.

Signed-off-by: Daniel Bittencourt <dcb@dcc.ufam.edu.br>