since the unit code within opm-parser is now a drop-in replacement,
this simplifies things and make them less error-prone.
unfortunately, this requires quite a few PRs. (most are pretty
trivial, though.)
Note that this patch does not introduce any real temperature
dependence but only changes the APIs for the viscosity and for the
density related methods. Note that I also don't like the fact that
this requires so many changes to so many files, but with the current
design of the property classes I cannot see a way to avoid this...
the largest change is that all classes below opm/core/props/pvt take
the PVT region index as an argument, the higher-level ones (i.e.,
BlackoilProps*) take cell indices.
Add new function is added that computes saturation from surface volumes
solving z = As for each cell. This function is used to compute an
intial guess to the saturations in initState_impl.hpp.
for some of these files this is needed to make to keep it compiling
after the next patch because the new ErrorMacros.hpp file will no
longer implicitly includes <iostream>. for the remaining files it is
just good style.
While at it, the includes for most of these files have been ordered in
order of decreasing abstraction level.
