HBASE-9547 Master could fail start if region server with system table is down

git-svn-id: https://svn.apache.org/repos/asf/hbase/branches/0.96@1523524 13f79535-47bb-0310-9956-ffa450edef68
HBASE-9529 Audit of hbase-client @InterfaceAudience.Public apis


git-svn-id: https://svn.apache.org/repos/asf/hbase/branches/0.96@1523541 13f79535-47bb-0310-9956-ffa450edef68