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

* do NOT use updateStaticWallProperties() in problem constructor
* correct calculation of maximum velocity
* add Laufer velocity profile
* update wall variable names

* this is the only test that failed after the changes in momentum upwind, thus the use of inertia terms is disabled
* use fixed times to write output
* do some clean-up

Somehow the upwinding and changes in navierstokes led to an additional Newton step

* rename old test for low Re testing

* 1p2c, 2p2c, test_donea (NavierStokes)

This patch reduces dependencies and makes usage of linear solvers more flexible, i.e. for two problems with different typetag

* Linear solvers don't need type tag anymore, in fact they don't need any template params
* the preconditioner block size is now provided for the solve method (see e.g. staggered newton controller)
* the amg has a convencience alias using a TypeTag but is "independent" through indirection via the traits

* [test][richards] Fix solver include
  (Used to compile before due to indirect include over newtoncontroller.

* make output more clear

* calculate the mass and volume fluxes over two different planes