also added ability to use Compositions as a std::hash in unordered_* types. Further added a constructor to build a Composition from a const CompositionAbstract&
MaskedComposition is a generally useful decorator, therefore instead of forcing callers to impliment it on their own, we have implimented it as part of libcomposition
It is sometimes useful for callers to be able to create new composition objects without overloading all the required methods. The CompositionDecorator acts as a simple translation layer which will pass any calls to virtual methods down to the next level of the composition stack (other than those which may have been overloaded by the caller)
Composition objects now must be built from vectors of molar abundances. Things such as mass fraction and number fraction are computed on the fly (with some caching for performance). This will allow for many fewer issues when converting from solver space to composition space.
BREAKING CHANGE: The entire old API has been broken. There is no longer any need to finalize. In fact the entire concept of finalization has been removed. Further, the entire CompositionEntry and GlobalComposition data structure has been removed. Any code written for the old version will no longer work and major reworking will be needed to use the new version.
The composition object is now a specialization of the abstract base CompositionAbstract. This interface enforces getters but not setters (those are left up to children). The intention here is that other code can specialize particular getters for cases where special handling (like unrestricted amounts of one species) are required.
Composition can now be placed in either number fraction or mass fraction mode and can (after finalization) convert between them. Subsets of compositions can also be made. Normalization has also been added to finalize. Tests have been added
