Use overridden class variable as default value_datatype instead of putting it into custom constructors
Use overridden class variable as default value_datatype instead of putting it into custom constructors

jonfoster/pyxb-upstream-mirror,CantemoInternal/pyxb,jonfoster/pyxb1,CantemoInternal/pyxb,balanced/PyXB,jonfoster/pyxb2,jonfoster/pyxb-upstream-mirror,jonfoster/pyxb2,pabigot/pyxb,jonfoster/pyxb-upstream-mirror,jonfoster/pyxb1,pabigot/pyxb,CantemoInternal/pyxb,balanced/PyXB,balanced/PyXB,jonfoster/pyxb2