Found an older implementation of Fluoroethane already under R161 .

Signed-off-by: Ian Bell <ian.h.bell@gmail.com>
Removed new implementation of R161

Signed-off-by: Ian Bell <ian.h.bell@gmail.com>
Added alias to old R161 file

Signed-off-by: Ian Bell <ian.h.bell@gmail.com>
Upper case aliases for any fluids that need them.  More refactoring.

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