AveragedTurbine, ScalarODE physics

I'm yet to be certain that I don't have a flaw in AveragedTurbine residuals, and I need to add some missing terms to the Jacobians, but the intrusive changes look to be in good shape now.

This probably shouldn't be merged until the scalar_residuals branch goes into libMesh, but it should actually compile against older libMesh just fine; it just won't give correct results.
But shitty uninformative names for init functions are a proud old libMesh tradition!  If GRINS starts being self-documenting it'll just make the rest of us look bad.