Removes PrintMenu and PrintMenuWithValues (replaced by calls to pm).
Adds ChooseStringIdWithValues to simplify old calls to PrintMenuWithValues.
Adds ChooseMenuItemId to simplify the ranking of abilities and attributes.
Changes getters to use intermediate variables during calculation and only sets the result once. This is to simplify renaming them later if needed.
Abstracts discipline points and background points to constants with getters to be overridden when adding ruleset support.