FLUME-2420. HDFS Bucketwriter must access sfWriters map only within synchronized blocks.

(chenshangan via Hari)
FLUME-2426. Support interceptors in the Embedded Agent

(Johny Rufus via Hari)
FLUME-1491. Support fetching configuration from Zookeeper.

(Ashish Paliwal via Hari)
FLUME-2337. export JAVA_HOME in flume-env.sh.template and increase heap size

(Roshan Naik via Hari)
Merge remote-tracking branch 'remotes/origin/trunk' into trunk