Add support for more than one cursor to be returned, like the MMapV1, in wiredTiger storage engine.
Allow storage engines to provide optimized random cursors for use by $sample
Allow mongodump to leverage parallelCollectionScan to speed up dumping of large collections
Implement parallelCollectionScan for WiredTiger
Support parallelCollectionScan command
parallelCollectionScan command only returns one cursor for WiredTiger