* allow setting a fixed value anywhere in the domain
* do not use boundaryType but a separate function to check for fixed cell
* set 1.0 on the diagonal in the system matrix and 0.0 for the off-diagonal entries
  to improve numerical accuracy

* internally forward to isOnWallAtPos
* needed for coupling

* get rid of fluidSystemPhaseIdx

* index of the pressure has to equal the one of the main component
* advection law does not need outflow information
* fix some reference solutions

Melanie Lipp authored Apr 25, 2018 and Dennis Gläser committed May 03, 2018

With contributions of Farid Mohammadi <farid.mohammadi@iws.uni-stuttgart.de>.

Fluid systems exported phase indices for wetting and nonwetting components. The fluid system
is not the right place to decide about wettability. This introduces wettingPhase() in the spatial
params which returns the index of the phase in the fluidsystem we consider the wetting phase.
This way wettability can change temporally and spatially.
Indices throughout the 2p/2p2c/2pnc nc and mpnc where renamed accordingly.

Dennis Gläser authored Apr 05, 2018 and Timo Koch committed Apr 15, 2018

Contributions by Timo Koch, Kilian Weishaupt.

features
* tests for zeroeqni and zeroeq2cni
* split update() in "classical" update() and updateRANSProperties()
* do not use asImp_() but virtual inheritance
* cleanup

* ransnc uses now nPhaseIdx = 1

navierstokes
* make vtkoutputfields more modular

rans
* move eddyViscosity functions to the specific rans implementation

* better distinguish between total mass balance and component mass balances

This commit affects all properties and member variables

This commit affects all properties and member variables