DSAKeyValue text

I propose the attached text for the DSAKeyValue section. I have tried to
be compatible with the existing material, so that at least any existing
DSA key would conform to the newer syntax. However, I really couldn't
figure out why the optional J parameter had been included. As far as I
can tell from the FIPS, it's just an internal parameter in the suggested
primality test algorithm and there is no reson to preserve it. It was
optional before and I'd be interested to hear if anyone was actually
generation DSAKeyValue elements with a J child element.

Thanks,
Donald