Fix :DEFAULT-INITARGS.
Fix :DEFAULT-INITARGS.

Default initargs weren't being computed properly when no initargs were
passed to MAKE-INSTANCE.
This also fixes an error when starting MED.

froggey/Mezzano,rvedam/Mezzano,froggey/Mezzano,varjagg/Mezzano,varjagg/Mezzano,rvedam/Mezzano