Deeper hierarchies in CMake.

See merge request walberla/walberla!407

[ADD] kernel for the VBondModel, viscous damping

See merge request walberla/walberla!394

[ADD] kernel for the VBondModel isotropic vdW contact

See merge request walberla/walberla!377

Display CTest results in Gitlab

See merge request walberla/walberla!402

[BUGFIX] handle failing of FindOpenMP

See merge request walberla/walberla!406

constructing an empty std::set has almost no cost

Update pybind11 to 2.6.2 release

See merge request walberla/walberla!404

Update ExprTk library

See merge request walberla/walberla!400

[ADD] constexpr to constructors of Matrix2 and MatrixMxN

See merge request walberla/walberla!401

making constructors constexpr

See merge request walberla/walberla!397

set cuda 17 to not required

See merge request walberla/walberla!398

Update pybind11 for Intel

See merge request walberla/walberla!396

[ADD] MESA-PD kernel for the VBondModel wall contact

See merge request walberla/walberla!375

Check whether LTO works before enabling it

Closes #140

See merge request walberla/walberla!395

make _r string literal constexpr

See merge request walberla/walberla!393

Eliminate most compiler-specific workarounds

See merge request walberla/walberla!387

Increase Code Coverage of MESA-PD

See merge request walberla/walberla!360

[UPDATE] readme and contributors

See merge request walberla/walberla!385

[ADD] radians <-> degree conversion functions

See merge request walberla/walberla!382