Added XNOR to the utilities. Signed-off-by: Stelian Ionescu <sionescu@common-lisp.net>
Added XNOR to the utilities.
Signed-off-by: Stelian Ionescu <c3ad3339b5ffc3418808e627431a7cb60f2334f3@common-lisp.net>

shamazmazum/iolib,deadtrickster/iolib,deadtrickster/iolib,dkochmanski/iolib,attila-lendvai/iolib,dkochmanski/iolib,shamazmazum/iolib,attila-lendvai/iolib,lispnik/iolib,dkochmanski/iolib,lispnik/iolib,tiago4orion/iolib,vsedach/iolib-simple-mux,attila-lendvai/iolib,sionescu/iolib,sionescu/iolib,sionescu/iolib,tiago4orion/iolib,shamazmazum/iolib,vsedach/iolib-simple-mux,lispnik/iolib,tiago4orion/iolib,deadtrickster/iolib