Just need to fill in the remaining terms and test, test, test

More testing is still needed to identify other issues

I am confused...

And add test

Stopped iteration if dx values are all < 0

And to python interface

Hours later...

Oddly this fixes the error in derivative, but it should have no impact

Temporaries were being returned when autodiff was being used, forceeval should fix it I think

Yet another battle with typing

It works!

* Add ability to access a single departure term in a multi-fluid model

* Bump version to dev