Converted parameter handling to be based on CAS code rather than on fluid name - easier to make changes since CAS codes are not variable

Signed-off-by: Ian Bell <ian.h.bell@gmail.com>
Cleaning up of CoolProp.h and CoolProp.cpp - non backwards-compatible changes.  Most parameters moved to within functions get_global_param_string and get_fluid_param_string.  Many wrappers are now broken

Signed-off-by: Ian Bell <ian.h.bell@gmail.com>
Further movement of code into separate files

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

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