HADOOP-9704. Write metrics sink plugin for Hadoop/Graphite (Chu Tong, Alex Newman and Babak Behzad via raviprak)

git-svn-id: https://svn.apache.org/repos/asf/hadoop/common/branches/branch-2@1599415 13f79535-47bb-0310-9956-ffa450edef68
HADOOP-10658. SSLFactory expects truststores being configured. Contributed by Alejandro Abdelnur.


git-svn-id: https://svn.apache.org/repos/asf/hadoop/common/branches/branch-2@1599436 13f79535-47bb-0310-9956-ffa450edef68