OAK-1926 - UnmergedBranch state growing with empty BranchCommit leading to performance degradation

Unmerged persistent branch revs would be purged upon start for current cluster

git-svn-id: https://svn.apache.org/repos/asf/jackrabbit/oak/trunk@1612825 13f79535-47bb-0310-9956-ffa450edef68
OAK-1983 Query: reduce debug log output

git-svn-id: https://svn.apache.org/repos/asf/jackrabbit/oak/trunk@1612828 13f79535-47bb-0310-9956-ffa450edef68