Generalize the signature date, so people are not expecting it to be updated...

Generalize the signature date, so people are not expecting it to be updated when the key expiration is bumped.

This was reported to the security contact as a problem, because the documented signature on the help pages was "expired" - because it doesn't makes sense to have to remember to update this documentation every time the key expiration is extended, we just remove those lines with dates, and make a note about how the output may not match exactly, but what the user should be looking for.