We should make it possible to enforce passwords that have 4 instead of just 3 character groups (like RequireStrongPassword) does now in Koha. This could be done as a new option to RequireStrongPassword that allows libraries to update from one setting to the other. We could also maybe rename the parameter to something like "PasswordComplexity". For legacy reasons I guess we'd also need a third option 'no requirements (strictly not recommended)'.