RfC447 - cannot delete sole patient case during registration process * consequence is patient cannot be found on registration search but also cannot be re-registered if it has an nhs number * can now only edit sole patient case, delete option only available for multiple patient cases
validate secondary diagnosis to prevent duplication of primary diagnosis * leads to loss of duplicate diagnosis data on rendering of Rose object by template or as_tree() * rename ConstraintMethods 'check_eq_with' to 'check_vial_id' for consistency with 'check_secondary_diagnosis' validation method
