Fix unit for streaming throughput in nodetool

patch by Olve Sæther Hansen; reviewed by yukim for CASSANDRA-7375
Fix unit for streaming throughput in nodetool

patch by Olve Sæther Hansen; reviewed by yukim for CASSANDRA-7375
Merge branch 'cassandra-2.0' into cassandra-2.1
Merge branch 'cassandra-2.1' into trunk