Since the Species object now stores its SpeciesThermoInterpType contents as a
shared_ptr, it is undesirable to have the Species constructor take this as a raw
pointer argument.
These objects do not need to know the index of the species within the phase, so
the new constructors do not take that as an argument.
For the NASA polynomial constructors, the order of the coefficients arrays in
the new constructors has been modified to match the conventional ordering of the
coefficients as written in thermo database files.
When instantiating a phase from a .cti file, do the conversion in memory,
without writing the XML representation to disk. This eliminates the unrequrested
XML files that Cantera normally generates, and also avoids errors when running
Cantera from a directory where the user does not have write permissons.