Set registered / waiting list info in index()
Reflect registered / waiting list status
Remove $useDbConfig property
Change wording
Create and implement __sendRefundEmail()
Fix two errors in sendRefundEmail()
Use __sendRefundEmail() in unregister_via_link()
Use variable message
Set message variables in unregister_via_link()
Reword to handle waiting list messages better
Emolliate 'this course is full' message
Change button label for waiting list