Wrote cronRefreshEdxprod.sh, which retrieves the latest edxapp-latest.sql.gz from deploy.prod.class.stanford.edu. Using the also new extractTableFromDump.sh the script extracts several tables from edxapp-latest.sql.gz: currently auth_user, courseware_studentmodule, and certificates_generatedcertificate. More tables can easily be added. These are loaded into new database 'edxprod' on datastage, mirroring the production system's tables of the same name in the platform database edxprod. Updated the README in the scripts subdirectory.