this is primary to allow models to check whether their assumptions are
valid for the given fluidsystem
also add the H2O-Air fluid system to the fluid systems test. this
caught a few issues!
it seems that the issue which triggered to make the tabulation "dumb"
was not related to the tabulation. I guess that it had something to do
with the fact that I used -ffast-math without -fno-finite-math-only...
we used to tabulate along the vapor pressure curve. it turns out that
if a phase is not present, the component might get queried for
unphysical values, which lead to breakdowns. now we just sample the
specified pressure range uniformly...
- make all headers in dumux/common and dumux/boxmodels/common self sustained,
i.e. that they can be included without any preconditions
- remove most irrelevant includes in the common code
- bring the 1p and 1p2c box model up to stable standard (accessor functions in
the volume and flux variable classes, make the 1p2c model work for
compressible fluids, various fixes the 1p2c test problem)
- change the isfluid-trail fluid system to standard SI units
- play around with timestep control if timestep ramp-up is enabled
(problem is still not solved, though)
- split the *properties.hh headers into the declaration of the properties and
definition of defaults for the common part of the box models as well as for
the 1p and 1p2c models
- put the indices structure for the 1p and 1p2c models into separate files
- introduce a base class for volume variables of the box models
