HBASE-7599 Port HBASE-6066 (low hanging read path improvements) to 0.94 (Devaraj Das)

git-svn-id: https://svn.apache.org/repos/asf/hbase/branches/0.94@1437237 13f79535-47bb-0310-9956-ffa450edef68
HBASE-7293 [replication] Remove dead sinks from ReplicationSource.currentPeers and pick new ones

git-svn-id: https://svn.apache.org/repos/asf/hbase/branches/0.94@1437238 13f79535-47bb-0310-9956-ffa450edef68
HBASE-7638 [0.94] region cache entry should only be removed on error if the error is from the server currently in cache (Sergey)



git-svn-id: https://svn.apache.org/repos/asf/hbase/branches/0.94@1437254 13f79535-47bb-0310-9956-ffa450edef68