tidy up migration script.
fix typo
create cli script for migration
Adding support for event_content_uploaded
MDL-35711 renamed finalize event - handling of drafts in new mod_assign
Removing hard-coded DB prefixes from db/upgrade.php
Merge pull request #42 from sam-moodle/fixHardCodedDBprefix

Removing hard-coded DB prefixes from db/upgrade.php