kafka-1620; Make kafka api protocol implementation public; patched by Anton Karamanov; reviewed by Jun Rao
kafka-1123; Broker IPv6 addresses parsed incorrectly; patched by Krzysztof Szafrański; reviewed by Jun Rao
KAFKA-1282 Disconnect idle socket connection in Selector; reviewed by Neha Narkhede and Jun Rao
kafka-1622; project shouldn't require signing to build; patched by Ivan Lyutov; reviewed by Jun Rao
Added SSL for Kafka

Minor fixes, cleanup

Refactoring

Fixed tests compilation error.
Updated according to requested changes: refactoring, minor edits.
Added basic functionality for new producer.
bug fixes after rebase
bug fix after rebase
updated tests after rebase
changed default security to false