Fixed reference state for R407F

Signed-off-by: Ian Bell <ian.h.bell@gmail.com>
Added hs_anchor state for all fluids

Signed-off-by: Ian Bell <ian.h.bell@gmail.com>
Updated ancillary curves for all fluids to use h-hanchor and s-sanchor in the fit

Signed-off-by: Ian Bell <ian.h.bell@gmail.com>
Merge branch 'master' of https://github.com/coolprop/coolprop