HBASE-10597 IOEngine#read() should return the number of bytes transferred



git-svn-id: https://svn.apache.org/repos/asf/hbase/trunk@1571445 13f79535-47bb-0310-9956-ffa450edef68
HBASE-10590 Update contents about tracing in the Reference Guide

git-svn-id: https://svn.apache.org/repos/asf/hbase/trunk@1571464 13f79535-47bb-0310-9956-ffa450edef68
HBASE-10556 Possible data loss due to non-handled DroppedSnapshotException for user-triggered flush from client/shell

git-svn-id: https://svn.apache.org/repos/asf/hbase/trunk@1571501 13f79535-47bb-0310-9956-ffa450edef68
HBASE-10581: ACL znode are left without PBed during upgrading hbase0.94* to hbase0.96+

git-svn-id: https://svn.apache.org/repos/asf/hbase/trunk@1571519 13f79535-47bb-0310-9956-ffa450edef68
HBASE-10582: 0.94->0.96 Upgrade: ACL can't be repopulated when ACL table contains row for table '-ROOT' or '.META.'

git-svn-id: https://svn.apache.org/repos/asf/hbase/trunk@1571529 13f79535-47bb-0310-9956-ffa450edef68