Merge branch 'release/0.1.0' into develop
Bump version to 0.1.1-SNAPSHOT
Clarify test description
Add shutdown() method to KafkaProducerApp
Clarify which code performs clean up at end of tests
AvroKafkaSinkBolt should not declare any output fields because it writes
to Kafka only, it does not emit any tuples
Update download link of Oracle JDK 6 for Mac OS X
built.sbt: add scalac option to warn about discarded values (-Ywarn-value-discard)
Explicitly return Unit value to prevent scalac warnings
Explicitly return Unit value in some tests to prevent scalac warnings
about discarding non-Unit values.
Remove Apache Maven repo because Storm and Kafka are in Maven Central
Force use of IPv4 instead of IPv6 (-Djava.net.preferIPv4Stack=true)

Notably, this prevents tests to fail on Mac OS X because of timeouts caused
by resolution of localhost and IPv6.  Storm uses a hardcoded test timeout of
5 seconds (see `TEST-TIMEOUT-MS` in `backtype.storm.testing.clj`), which is
often exceeded because of the long duration of resolution on Mac OS X
when IPv6 is enabled.

For more details on the timeout issue see:
https://issues.apache.org/jira/browse/STORM-70
https://issues.apache.org/jira/browse/ZOOKEEPER-1476
Use Storm 0.9.2
ZooKeeperEmbedded: set default port to 2181
Explain that upcoming ZK 3.5.0 will provide better controls to configure JMX
Explicitly define return type of connectString
Expose hostname and port of ZooKeeperEmbedded
zkclient: exclude ZooKeeper dependency
KafkaEmbedded: use randomized local log.dirs, and remove it on shutdown
KafkaSpec: use random ZK port