don't use remove() on head in cachedstore's double linked list because of https://issues.scala-lang.org/browse/SI-3970
tweak kv test to trigger NPE when test is run with Scala 2.8.1. Validate that patch fixes the bug. Add brackets in if else in cached store for style.
SAMZA-3 BrokerProxy deadlocks if messages aren't polled from all streams
Merge branch 'master' of https://git-wip-us.apache.org/repos/asf/incubator-samza