arg-comp auxiliaries constrain REST of COMPS list to be aux-minus-list

[emilymbender]

The argument composition auxiliaries continue to make generation difficult. One thing that could help some (provided we aren't abandoning this analysis for the more efficient one) is to make the REST of the COMPS list be aux-minus-list:

aux-minus-list := list.
aux-minus-cons := aux-minus-list & cons &
  [ FIRST [ LOCAL.CAT.HEAD.AUX - ],
    REST  aux-minus-list ].
aux-minus-null := aux-minus-list & null.

There probably also need to be mutual subtypes between aux-minus-cons and ocons / aux-minus-null and onull, too.