make attrs optional in head and archdesc for undeprecated dtd driver
make attrs optional in head and archdesc for undeprecated dtd driver

informaticmonad/EAD3,SAA-SDT/EAD-Revision,SAA-SDT/EAD3,informaticmonad/EAD3,SAA-SDT/EAD-Revision,SAA-SDT/EAD3