add metachange event, when broker connection is lost, should check the metadata first
merge the kafka-node 0.7.0 to my repo
fix issue when logs contain chinese producer encode problem
add a flag to control consume speed. when user deal with all the logs the continue to read the data
support read same topic and multi partition logs

configure like this
{topic: 'nelo2-test-logs', partition: 1},
{topic: 'nelo2-test-logs', partition: 0},