* specialized for box/cc

we now have the following levels of type tags:

- basic numerical model
- linear solver type tag
- discretization scheme-specific type tag
- physics-related type tag (e.g. pmflow)
- problem-specific type tag

the dual grid index set now does not contain the data on the global scv indices
that are connected to the faces. The local data is only available in the iv index set.
This should be better for methods other than the mpfa-o method, as in those the local mappings
of the dual grid index set is maybe useless (e.g. for the mpfa-l scheme).

TODO: implement ficks and fouriers law, as well as the interaction volume data handles
accordingly for problems involving diffusion/heat conduction

Dennis Gläser authored Feb 07, 2017 and Timo Koch committed Feb 17, 2017

we do not allow for different implementations of the globalfvgeometry
class for the different mpfa methods anymore. If this ever occurs to be
necessary one might reintroduce this. Until then, we opt for having one file
less.

Dennis Gläser authored Oct 12, 2016 and Timo Koch committed Nov 23, 2016

The treatment of mixed BC is questionable for cc methods. Not allowing
for it enables us to not have to store n interaction volume seeds at the boundary.

Dennis Gläser authored Sep 16, 2016 and Timo Koch committed Nov 23, 2016

The support for interior boundaries will be handled explicitly in the
facet coupling implementation in the multidimension module. Its support
in the standard mpfa implementation causes an overhead which we don't want
here since interior boundaries do not have to be available for standard models.