Implement first except for All
Implement first except for All

pabigot/pyxb,balanced/PyXB,balanced/PyXB,CantemoInternal/pyxb,balanced/PyXB,CantemoInternal/pyxb,jonfoster/pyxb-upstream-mirror,jonfoster/pyxb-upstream-mirror,jonfoster/pyxb2,jonfoster/pyxb-upstream-mirror,CantemoInternal/pyxb,jonfoster/pyxb2,jonfoster/pyxb2,pabigot/pyxb