[swe][viscous] Do not require spatial params to implement friction law

See merge request !2492

[example][1ptracer] Use library-independent portable random distribution

See merge request !2484

[test][1pnc] Separate properties into their own header

See merge request !2488

[test][1p] Separate properties into their own header

See merge request !2487

Fix/missing includes

See merge request !2486

Fix/various small

See merge request !2485

Installdumux.py with dumux and dune versions as a command-line options

Closes #992

See merge request !2481

[shallowwater][diffusion] add turbulent diffusion to shallow water

Closes #706

See merge request !2243

[pnm] Improve grid generation

See merge request !2483

assemble matrix only once in the linear pde solver

See merge request !2239

Bernd Flemisch authored Sep 08, 2020 and Timo Koch committed Feb 26, 2021

So far, the `LinearPDESolver` (re)assembles the matrix in its
`solve` function unconditionally. This might be unnecessary if the
matrix did not change compared to the previous call to `solve`.
Make a first attempt to avoid the unnecessary calculation by
adding a corresponding control flag.

Feature/box scvf num outside scvs

See merge request !2469