[porousmediumflow] fix problem constructor

Closes #486

See merge request !942

The Problem constructor called the SpatialParams constructor in the
intializer list, passing itself via `this->asImp()`. This lead to
segfaults since the constructor of the ParentType had not been called
before. Fix by copying the working constructor instead of calling it.

[box] fix scvf corner computation for tetrahedra

See merge request !941

[pmflow] Add problem constructor getting the spatial params

Closes #459

See merge request !938

Feature/remove philtophob

Closes #483

See merge request !935

[io][staggered] use new constructor argument order of output module

See merge request !936

Remove buggy and obsolete PhilToPhobLaw -> use wettingPhase() in spatial params to set the wetting phase index

What was broken:
The test used philtophob law which used the wrong residual saturations. It went into efftoabslaw with
the non-wetting saturation so swr and snr where the wrong way around. It also overwrote the krw/krn function
of the material law in use with a quadratic/cubic law. It also defined the capillary pressure negative but then
it would be pc = pw-pn.

What was fixed:
Use the wettingPhase function instead to make the gas phase the wetting phase

This changed:
- the pw solution as swr and snr were corrected (the wrong way around pw was equal)
- the pc solution because it is now positite
- the mobilities as they didn't use the real van genuchten curves

Feature/nonconforming vtk output

See merge request !932

Dennis Gläser authored 6 years ago and Timo Koch committed 6 years ago

This commit also gets rid of compatibility with Dune 2.5

[2p] Update incompressible reference both mpfa and tpfa pass with same solution

See merge request !933

[2p][test] Update fracture test reference

See merge request !931

[fickslaw][network] Consider that transmissibilities can be zero

See merge request !930

Free the Box Method's Darcy's law from TypeTag

See merge request !929

[privarswitchNetwonSolver] Change final to override for virtual methods

See merge request !927

* allow inheritance from this class

Feature/extrusion factor staggered

See merge request !914

Freeflow/lowrekepsilon cleanup

See merge request !911

[freeflow] Implement Neumann BC for momentum

See merge request !871

[staggered] Do not call sourceAtPos in localRes

See merge request !912

Fix/box scvf construction

See merge request !924