Default to shared print area for all courses

[perliedman]

An event has a print area, and each course can have its own print area. As implemented now, each course always has it's own print area, and editing the area only affects the course.

In most cases, it's probably better to default to a shared print area for all courses, and only give the option to set an individual print area.

• Rewrite print area logic to first check if the course has a print area, and fall back to the event's print area if there isn't one
• Update UI so it's possible to:
  • Edit the shared print area
  • Create a print area specific for a single course
  • Delete a course's specific area and again fall back to the event's print area