HADOOP-9594 commons-math

git-svn-id: https://svn.apache.org/repos/asf/hadoop/common/branches/branch-2@1541667 13f79535-47bb-0310-9956-ffa450edef68
HADOOP-9594 commons-math

git-svn-id: https://svn.apache.org/repos/asf/hadoop/common/branches/branch-2@1541668 13f79535-47bb-0310-9956-ffa450edef68