Added netperf test module

This module brings netperf tool support. Netperf serves to measuring network
throughput. It is required to have at least 2 machines in the pool, one for
server, rest for clients. If you insert threshold option in recipe, test will
determine, whether the throughput is higher or lower than the threshold, if no
threshold value is inserted, test will just measure throughput.

Signed-off-by: Jiri Prochazka <jprochaz@redhat.com>
Signed-off-by: Jiri Pirko <jiri@resnulli.us>
README: add Jiri Prochazka and fix Radek's email

Signed-off-by: Jiri Pirko <jiri@resnulli.us>