This reverts commit b6adad23.
This reverts commit a9cdfeee.
This reverts commit a9bc2b1b.

it's now properly working from within stuff's magic

this solves problems in new dune-alugrid code, that
actually mandates prepost adapt calls

index for accessing corners of an intersection
could become oob if #corners < #intersections

apparently it's mandatory to include dune/alugrid/dgf.hh
first and never dune/alugrid/grid.hh

dune-fem bump to e596fced2d058066e651d4a81c27cea2703802af
introduced failure

- rename from InStationaryDefaultDiscretization/NonStationaryDiscretizationInterface
to HyperbolicFVDefaultDiscretization/FVDiscretizationInterface
- add support for all numerical fluxes and timesteppers that are currently
implemented
- adjust problems/tests