CVS check in time.

I've checked in the rest of multithreaded code, it works but probably needs a rewrite.

Core Data and binding can be a little tricky with threads, to the point that binding should really used on the main thread and Core data is only really thread safe because you can lock it at Persistent Store level. I've modified the existing code with these constraints but I'm still left with pending changes for some reason. There's a method to call to process pending changes, and that's why it works at the moment,  but I'd rather not have them in the first place

That leaves bug fixes to go before a release.