Call the generate constants module script when generating sdist for pypi

Signed-off-by: Ian Bell <ian.h.bell@gmail.com>
Merge branch 'master' into vectorize_PropsSI
sdist preparation works again

Signed-off-by: Ian Bell <ian.h.bell@gmail.com>
Merge branch 'master' into vectorize_PropsSI
Fixed EES builder and expose extract_backend

Signed-off-by: Ian Bell <ian.h.bell@gmail.com>