Added example file for LibreOffice

Signed-off-by: Ian Bell <ian.h.bell@gmail.com>
Fixed wrapper to close https://github.com/ibell/coolprop/issues/181

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

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