- Add help for 'payment account' field in the enrol instance form
- Remove MOODLE_INTERNALs when not necessary
- Add $userid to deliver_order
- Check if provider classes implement the provider interface
- Rename get_cost to get_payable
- get_payable returns payable object
- Improve registerEventListeners and added init
- Rename payment\provider to payment\service_provider
Also create the infrastructure to let components know when they have to
deliver what they sold. We are going to use namespace functions instead
of traditional callbacks.
Shamim Rezaie