DSA2 default status

[Robert J. Hansen]

David Shaw wrote:
> Thoughts?

Depending on how soon the V5 key spec is ready, we may want to fold
everything in all at once.  Changing defaults isn't a big deal, but it
tends to get pushback from users who seem to think their old keys are
somehow broken or defective (since otherwise, "they wouldn't have
changed the defaults").

If V5 is going to be more than six months or so, though, then I think
enabling DSA2 by default should be done now.