anchor.diff:  ----
   g++ -std=c++14 -fopenmp -mavx -mfma -DTHRUST_DEVICE_SYSTEM=THRUST_DEVICE_SYSTEM_OMP -Ipath/to/feltor/inc -Ipath/to/include test.cpp -o test
   export OMP_NUM_THREADS=4
  +./test
  +----
  +If you do not want any parallelization, you can use a single thread version
  +[source,sh]
  +----
  +g++ -std=c++14 -mavx -mfma -DTHRUST_DEVICE_SYSTEM=THRUST_DEVICE_SYSTEM_CPU -Ipath/to/feltor/inc -Ipath/to/include test.cpp -o test
   ./test
   ----
   
  
positive.code: ----
  cd path/to/feltor/inc/dg
  
  make blas_mpib device=omp  # (for MPI+OpenMP)
  # or
  make blas_mpib device=gpu # (for MPI+GPU, requires CUDA-aware MPI installation)
  
negative.code: ----
  cd path/to/feltor/src/toefl # or any other project in the src folder
  
  make toeflR device=gpu     # (compile for gpu, cpu or omp)
  ./toeflR <inputfile.json>  # (behold a live simulation with glfw output on screen)
  # or
  make toefl_hpc device=gpu  # (compile for gpu, cpu or omp)
  ./toefl_hpc <inputfile.json> <outputfile.nc> # (a single node simulation with output stored in a file)
  # or
  make toefl_mpi device=omp  # (compile for gpu, cpu or omp)
  export OMP_NUM_THREADS=2   # (set OpenMP thread number to 1 for pure MPI)
  echo 2 2 | mpirun -n 4 ./toefl_mpi <inputfile.json> <outputfile.nc>
  # (a multi node simulation with now in total 8 threads with output stored in a file)
  