typical examples of Dymola AutoFormatting nonsense - even with Advanced.AutoFormatting = false; !!!
Types and Choices are now part of Interfaces, not part of Interfaces.PartialHelmholtzMedium

(moving them out of the partial package, that is)
more examples of Dymola AutoFormatting nonsense - even with Advanced.AutoFormatting = false; !!!
some renaming due to moving Types and Choices
more examples of Dymola AutoFormatting nonsense - even with Advanced.AutoFormatting = false; !!!
changing paths in HelmholtzFluids due to moving Types and Choices
new tests, contributed by @casella, see issue #22

Butane passes the test, Helium does not
new tests, contributed by @casella, see issue #22