/*
 *  call-seq:
 *     dtable.modulo(number)       ->  a_dtable
 *     dtable.mod(number)          ->  a_dtable
 *     dtable.modulo(other)        ->  a_dtable
 *     dtable.mod(other)           ->  a_dtable
 *     dtable % number             ->  a_dtable
 *     dtable % other              ->  a_dtable
 *  
 *  When argument is a number, this operation returns a copy of _dtable_ with each entry x replaced by x % _number_.
 *  When argument is a data array, this operation returns a copy of _dtable_ with each entry x replaced
 *  by x % the corresponding entry in the _other_ data array.
 *     
 */ VALUE dtable_mod(VALUE ary, VALUE arg) {