[STORM-1975] Support default value for KafkaBolt

[darionyaphet]

STORM-1975 Support default value for KafkaBolt

Support some default values (acks , key and value serializer) for kafka bolt

[harshach]

@darionyaphet given that old consumer api is deprecated and we've new storm-kafka-client lets get our development efforts with storm-kafka-client. Unless there is a bug I am against adding any new features to storm-kafka.

[darionyaphet]

@harshachStorm-kafka-client is a new spout to consume data from Kafka . It seems not include KafkaBolt. Is it good to port Storm-kafka's KafkaBolt into Storm-kafka-client ?

[ptgoetz]

@harshach@darionyaphet I don't think we're in a position to deprecate storm-kafka yet for two reasons:

1. storm-kafka-client does not have feature parity with storm-kafka yet (e.g. bolt, Trident support)
2. storm-kafka-client requires kafka 0.10.x. It will take some time for all users to upgrade to that version.