Removed unused compression argument to rd_kafka_op_reply*
Added statistics emitter

An application may subscribe to librdkafka statistics by setting
the "statistics.interval.ms" configurarion property to non-zero and
registering a stats callback that will be called from rd_kafka_poll().

The statistics is JSON encoded.
Less noisy 0001 test
Regression test results are now color coded
Regression tests: honor TEST_LEVEL env variable
Added statistics support (-T) to rdkafka_performance
Added quiet flag (-q) to rdkafka_performance
Better handling when running rdkafka_performance in "forever" mode (no -c ..)
Updated README with statistics info and node-kafka