KafkaInputDStream improvements. Allows more Kafka configurability
fixing memory leak in kafka MessageHandler
removing dependency on ZookeeperConsumerConnector + purging last relic of kafka reliability that never solidified (ie- setOffsets)
keeping JavaStreamingContext in sync with StreamingContext + adding comments for better clarity
fixing autooffset.reset behavior when set to 'largest'
Merge pull request #527 from Reinvigorate/sm-kafka-cleanup

KafkaInputDStream fixes and improvements