* SkillOrClass is converted to RequiredSkill (and then field can contain skill id only)
* Field ZoneOrSort has no longer a function in quest requirement, and RequiredClasses must be used instead where class limits are expected.
To restrict a quest to one class or more, use bitmask of class in RequiredClasses. RequiredSkill works like before.
Signed-off-by: NoFantasy <nofantasy@nf.no>