[lisp/geo/geopack.l] support vplus other than 3-length vector
[lisp/geo/geopack.l] support vplus other than 3-length vector

bmagyar/EusLisp,aginika/EusLisp,aginika/EusLisp,aginika/EusLisp,wkentaro/EusLisp,bmagyar/EusLisp,bmagyar/EusLisp,aginika/EusLisp,bmagyar/EusLisp,wkentaro/EusLisp,wkentaro/EusLisp,wkentaro/EusLisp