HBASE-10094 Add batching to HLogPerformanceEvaluation

git-svn-id: https://svn.apache.org/repos/asf/hbase/branches/0.96@1548913 13f79535-47bb-0310-9956-ffa450edef68
HBASE-10048 Add hlog number metric in regionserver

git-svn-id: https://svn.apache.org/repos/asf/hbase/branches/0.96@1548917 13f79535-47bb-0310-9956-ffa450edef68