Checklists may now be split into individual sections made up
of <pages> containing the <item> tags. Each page is displayed
individually with Previous/Next buttons to allow navigation.
Checklists items also support <marker> tags. These display
a marker when a ? button is pressed next to the checklist item.
The format is identical to that of the tutorial system.
Checklist items now support a <condition> element that evaluates
when the checklist item is complete, and is used to provide color
coding in the checklist dialog.