staggered boundary generation: direction index should point to fluid cell when...

See merge request !299

codegen cmake: add to PYTHONPATH instead of overwriting

See merge request !300

Make codegen cmake integration symlink-compatible

See merge request !301

staggered boundary generation: direction index should point to fluid cell when inner_or_boundary=False

In that case, the index vector contains the boundary cells, so the direction should point to the fluid cell.
When inner_or_boundary=True, the index vector contains the fluid cells and the direction points to the boundary cell.

[BUGFIX] missing executables

See merge request !296

Since some benchmarks/tutorials are registered as tests they have to be
built in order to run.

Allowed different field layouts in LBM codegen

Closes #119

See merge request !294

Added warning if no SIMD instruction could be determined, adapted field layouts in all tests and benchmarks

FFT: show error when using with MPI_COMM_WORLD

See merge request !293

enable mesa_pd codegen for ci

See merge request !292

heat conduction and thermal expansion showcase

See merge request !284

moved coverage image to local registry

See merge request !291

Moved from heat capacity to specific heat
to take into account individual mass of a particle.

Use serial I/O instead of MPI-IO for certain versions of OpenMPI

See merge request walberla/walberla!282

removed mrt3 from each test case

See merge request walberla/walberla!287

optimize build time

See merge request walberla/walberla!290

enable clang10

See merge request walberla/walberla!288