HBASE-9090 cleanup snapshot tests setup/teardown code

git-svn-id: https://svn.apache.org/repos/asf/hbase/trunk@1508801 13f79535-47bb-0310-9956-ffa450edef68
HBASE-8548  postOpen hook called twice

git-svn-id: https://svn.apache.org/repos/asf/hbase/trunk@1508895 13f79535-47bb-0310-9956-ffa450edef68