[2p2c] Remove useKelvinVaporPressure as property and model trait. Set directly for the fluid system

Closes #488

See merge request !972

[fvgridvars] remove assertion in prevGridVolVars() return function

See merge request !974

We always call this function, since we instantiate a local view for the
previous volume variables independent of if the problem is stationary or
instationary. We simply don't call bind on it for stationary problems.
Thus, the assertion fails for all stationary problems.

[navierstokes][1d] 1d implementation of the staggered Navier-Stokes model

See merge request !960

Feature/update gridvariables aftergridadaption

See merge request !971

[bugfix] auto parameters are not allowed in C++14

See merge request !970

[cmake] Remove dune2.5 specific stuff

See merge request !961

[freeflow] Improve outflow for outflow-tangential velocities

See merge request !959

Freeflow/diffusive enthalpy

See merge request !949

[freeflow] Remove the atPos functions on the model level

See merge request !956

How these fluxes are used later-on should be treated there.

Extract global position from grid

Closes #470

See merge request !934

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

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

[cleanup] Remove const on return type in return by value functions

See merge request !955

[boxdfm][geomhelper] remove obsolete assertion

See merge request !954

Drop support for dune 2.5

See merge request !939

Feature/boxdfm

See merge request !946

Feature/test improve vtu coordinate sort

See merge request !952