Lots happened: new MySQL function 'wasCertified()'; added CLI option 'onCluster' to manageEdxDb.py. If provided, uses transformGivenLogFilesOnCluster.sh instead of transformGivenLogFiles.sh in lower layers. The latter uses Gnu Parallel to run transforms on cores of the local machine. The former instead expects to run on a compute cluster. In that case selection of files to transform is done via a lock-and-rename of files in the to-do directory. Many fly-by bug fixes.