KAFKA-921; Expose max lag and min fetch rate mbeans for consumers and replica fetchers; reviewed by Jun Rao.
KAFKA-928 new topics may not be processed after ZK session expiration in controller; reviewed by Jun Rao
kafka-927; Integrate controlled shutdown into kafka shutdown hook; patched by Sriram Subramanian; reviewed by Neha Narkhede and Jun Rao
kafka-903; Attempt to swap the new high watermark file with the old one failed on Windows; patched by Jun Rao; reviewed by Neha Narkhede, Jay Kreps and Sriram Subramania
KAFKA-905 Logs can have same offsets causing recovery failure; reviewed by Jun, Neha and Jay
kafka-931; make zookeeper.connect a required property; patched by Jun Rao; reviewed by Neha Narkhede
Merge branch '0.8' of https://git-wip-us.apache.org/repos/asf/kafka into 0.8