Generic CO2 Component

We currently have a simpleco2.hh for when CO2 is used as an ideal gas and a co2.hh, which uses the values from the CO2Tables.

We would like to have a CO2 component that chooses automatically between a "simple CO2" formulation (when used in the ideal gas regime) or the tabulated values from the CO2 tables (when used in the super-critical regime) or some interpolation between the two.

• Define/Look up regime for ideal gas and super-critical state
• Think of good and efficient interpolation
• implement all

Discussion:

Should we include the option to "force" the use of either one, in case you really want to use CO2-Tables or the ideal gas law all the time?