HBASE-8895 Misc: replace hbase.client.retries.number w/ define and remove unused imports

git-svn-id: https://svn.apache.org/repos/asf/hbase/branches/0.95@1500992 13f79535-47bb-0310-9956-ffa450edef68
HBASE-8900 TestRSKilledWhenMasterInitializing.testCorrectnessWhenMasterFailOver is flakey

git-svn-id: https://svn.apache.org/repos/asf/hbase/branches/0.95@1501023 13f79535-47bb-0310-9956-ffa450edef68