STORM-399 update KafkaConfig.maxOffsetBehind default to be Long.MAX_VALUE
Merge branch 'STORM-399-kafka-spout-increase-default' of https://github.com/curtisallen/incubator-storm into STORM-399

STORM-399: Kafka Spout defaulting to latest offset when current offset
is older then 100k
Updating contributors and CHANGELOG for STORM-399