HBASE-8547. Fix java.lang.RuntimeException: Cached an already cached block (Addendum2 to check cached buffers for equality)

git-svn-id: https://svn.apache.org/repos/asf/hbase/branches/0.95@1483478 13f79535-47bb-0310-9956-ffa450edef68
HBASE-8505 References to split daughters should not be deleted separately from parent META entry

git-svn-id: https://svn.apache.org/repos/asf/hbase/branches/0.95@1483483 13f79535-47bb-0310-9956-ffa450edef68
Merge remote branch 'origin/0.95' into 0.95-gd