OAK-2318: DocumentNodeStore.diffManyChildren() reads too many nodes

Merged revision 1643767 from trunk

git-svn-id: https://svn.apache.org/repos/asf/jackrabbit/oak/branches/1.0@1643773 13f79535-47bb-0310-9956-ffa450edef68
OAK-2322 Compaction estimation includes all data segments
 - merged r1643774



git-svn-id: https://svn.apache.org/repos/asf/jackrabbit/oak/branches/1.0@1643775 13f79535-47bb-0310-9956-ffa450edef68
OAK-2322 Compaction estimation includes all data segments
 - made SegmentPropertyState public



git-svn-id: https://svn.apache.org/repos/asf/jackrabbit/oak/branches/1.0@1643776 13f79535-47bb-0310-9956-ffa450edef68