More issa changes.

After some thinking and some other bib-related work. I've decided to make issa create new copies as pre-cat bibs like it should have to begin with. Since there is an installed base (however small) of issa users, this new feature will be optional, but turned on by default, so any it will be there for any new installations. If an existing installation wants to use the new feature, then they'll need to update their issa code and add the option in their configuration file. I'll explain how it works and how to activate the feature once I've actually coded the solution.