Resolved issue for p,h for subcooled liquid

Signed-off-by: Ian Bell <ian.h.bell@gmail.com>
Removed all 'using namespace std'

Signed-off-by: Ian Bell <ian.h.bell@gmail.com>
Fixed length of component vector for refprop with specified composition for mixture

Signed-off-by: Ian Bell <ian.h.bell@gmail.com>
Phase envelope constructed in two parts until max(abs(K-1)) is less than 1.01 on each branch

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