* CMake yielded an error with dune master

[doc] Remove section about outdated highlighting file

See merge request !511

Some links were outdated/not working.

[freeflow] Add files for estimating the properties of a turbulence flow

See merge request !463

Handbook/improvements for release

See merge request !411

Cleanup/fs 338 3pwateroil

Fixes #338 and #337.

See merge request !261

Feature/use adl for std functions

* `std::swap` and `dumux/common` was cleaned up
* much more needs to be done
* I found a bunch of other clean-up stuff

See merge request !259

The changing constitutive relations task in exercise 1 previously was about
exchanging the EffToAbsLaw with a LinearMaterial law. It makes more sense to
replace the RegularizedBrooksCorey.
The description in the handbook was adapted accordingly.

Fill missing entries in feature table

*Delete unused entries

Include new features, add links to models and test problems

Should even work when they stick to version 3.0, but
not vice versa.

Testing links for implicit models