fixes overriding Map attributes with user-defined value, ivar, or mask
fixes overriding Map attributes with user-defined value, ivar, or mask

bretthandrews/marvin,albireox/marvin,albireox/marvin,bretthandrews/marvin,sdss/marvin,bretthandrews/marvin,sdss/marvin,sdss/marvin,sdss/marvin,bretthandrews/marvin,albireox/marvin,albireox/marvin