[folder structure] move porousmediumflow/implicit/nonisothermal to porousmediumflow/nonisothermal/implicit

Added the use of convenience functions also in the 2pncminlocalresidual,
which i forgot in the previous commit 2c0b5..b82c76b4.

2pnc and 2pncmin are now using only convenience functions as required in FS211
instead of directly calling the fluidstate.
The necessary convenienience functions (mass and moleFraction, molarity) were implemented.

Added #if HAVE_MPI before class instantiation of NonoverlappingSolverTraits
and OverlappingSolverTraits.

Reviewed by Bernd.

Fix shadowing warning in boundingboxtree.h



See merge request !50

[doxygen] Add auto-deletion of the html folder, so that doxygen always builds a new documentation



See merge request !49

The function definition requires brackets (). The function keyword
is unnecessary and results in less portable shell code, see:
http://unix.stackexchange.com/questions/73750/difference-between-function-foo-and-foo

Instead of calling fluidstate().FLUIDPROPERTY(), the now implemented
convenience functions are used.

Reviewed by kweis

Feature/tensorgrid

Implements the feature of yasp grid, which is able to take an arbitrary number of refine/interface points. Between these points the number of cells as well as the grading can be chosen individually.

See merge request !47

This changes the reference solutions.

This requires updating the reference solutions.
For mpnckinetic it was not able to check, whether the reference solution was already broken before.

The grids gets a position array from which the grid is constructed. Optional arguments are the number of cells and the grading

[gridcreator] Deprecate simplex and cube grid creator

Structured grids can be defined (since dumux 2.8 / dune 2.4)
via the input file like follows:

```ini
[Grid]
LowerLeft = 0 0 0
UpperRight = 4 5 6
Cells = 2 2 6
CellType = Simplex
Refinement = 1         # optional
```

Note that Simplex is only available for grids supporting simplices.
For multidomain applications the property GridParameterGroup can be
set in each sub problem if you need to define different grids for
the subdomains in the same input file.

Dgf grids can be set as usual with the default grid creator

```ini
[Grid]
File = my.dgf
```

See merge request !44

Add guardians for wrong boundary types for the mass balance in the free flow domain.

Avoids undesired behavior in case a "not-defined" boundary type is set.

See merge request !46

[2pminc][bugfix] Fix compiler error variable unknown

This is a quick fix that dumux compiles again.
It looks like the 2pminc needs some cleanup (-> dumux-day?)

See merge request !48

Structured grids can be defined (since dumux 2.8 / dune 2.4)
via the input file like follows:

[Grid]
LowerLeft = 0 0 0
UpperRight = 4 5 6
Cells = 2 2 6
CellType = Simplex
Refinement = 1         # optional

Note that Simplex is only available for grids supporting simplices.
For multidomain applications the property GridParameterGroup can be
set in each sub problem if you need to define different grids for
the subdomains in the same input file.

DGF
The new default gridcreator (since dumux 2.8) has the
identical functionality with identical interface. Just specify

[Grid]
File = bla.dgf

Update documentation

Feature/valgrind with cmake



See merge request !43

[bugfix] Make test require executable

The test falsely required an executable with the name of the test
instead of the name of the executable. As the comment correctly states
the test needs the executable to run not a test target..

See merge request !45

The test falsely required an executable with the name of the test
instead of the name of the executable. As the comment correctly states
the test needs the executable to run not a test target..