refactor form error handling: * almost everything is in the base form class, with other form errors related code * deprecate form_field_error in favor of field_error and format_error on the renderer * fix pb with js localization of errors by properly using field.role_name() * rename 'errors' into 'error' in forminfo to avoid confusion

drop_attribute('CWEType', 'meta')
drop_attribute('CWRType', 'meta')