* We require the signature std::string(int, int) signature for all pv
names functions passed to load solution. You can still wrap a function
that just takes a privar index into a lambda with these two arguments.

* We make FluidSystem an optional template parameter for all functions
that don't make use of it. This way they can be also used directly in
loadSolution when not using the convenience free function pvNames.

* We return a function from the convenience free function now to be able
to include the param group

Bernd Flemisch authored Jul 27, 2018 and Timo Koch committed Aug 10, 2018

Missing: elastic, mpnc, nonequilibrium, mineralization.

Kilian Weishaupt authored Jul 19, 2018 and Thomas Fetzer committed Jul 20, 2018

* remove now obsolete NavierStokesNCIndices

* this makes coupling with, e.g., Darcy domains much easiert, as the same fluid system can be used for both domains
* add fluidSystemPhaseIdx to model traits and indices, where necessary
* add some docu

Fix problem with sanitizelinks.sh

* Do not pass base class as template parameter for compositional
  localRes and fluxVars

* instead pass base class as template parameter for rans localRes
  and fluxVars

* add test
* add PDELab solution for comparison
* speed-up by avoid calling getparam
* improve determination of the gradient
* increase verbosity for comparison