HBASE-7174 [snapshots] Refactor snapshot file cleaner cache to use Snapshot FileVisitor (Matteo Bertozzi)



git-svn-id: https://svn.apache.org/repos/asf/hbase/branches/hbase-7290@1445792 13f79535-47bb-0310-9956-ffa450edef68
HBASE-7311 Add snapshot information to hbase master webui (Matteo Bertozzi)



git-svn-id: https://svn.apache.org/repos/asf/hbase/branches/hbase-7290@1445794 13f79535-47bb-0310-9956-ffa450edef68