Improve checklist_print_overview()

1. Add a new global setting - show only updateable checklists
2. If that setting is enabled then CHECKLIST_MARKING_TEACHER checklists
will not be shown in 'my moodle'
3. If that setting is enabled and the user does not have the capability
'updateown', then skip that checklist
4. 'CHECKLIST_MARKING_BOTH' checklists should also be hidden, as
students cannot affect the progress bar, only teachers can update the
progress bar.
5. Site Admin's will not see any checklist notices