validator-0_6_6.tar.gz updated

I've recreated validator-0_6_6.tar.gz on v.w.o [1]; the previous one was
apparently created from an unclean development dir somewhere and
contained some backup files as well as other junk that should not have
been there.  The sgml-lib tarball is ok, did not touch it.  (See
commentary in misc/mkrelease.sh for info how to create clean release
tarballs.)

[1] Yeah, brown paper bag updates should be avoided...