PHP-1258: Be able to skip skip a test based on storage engine
Mark the parallelCollectionScan test as mmapv1 only, as other engines don't support this yet.
Merged pull request #778
PHP-1276: s/cmd/command/ in 2.8
Merged pull request #779
PHP-1276: Pass proper wireprotocol flags when executing commands on secondaries
Merged pull request #780