moved generic blockforest creation functions from pe/CreateWorld to blockforest/Initialization.h

Removed unused LBM test case

Closes #83

See merge request walberla/walberla!176

Resolve "possible division by zero in DynamicDiffusive load balancer"

Closes #41

See merge request walberla/walberla!178

use the general classes instead. they support levelwise load
balancing via a constructor parameter

default is levelwise for backward compatibility

Resolve "introduce contact based pe load balancing"

Closes #82

See merge request walberla/walberla!174

Resolve "possible segfault in DynamicDiffusive load balancer"

Closes #42

See merge request walberla/walberla!175

Removed boost exception

See merge request walberla/walberla!177

Fix unintialized warning in Config.h when compiling with undef. sanitizer

Closes #39

See merge request walberla/walberla!170

Fix error when writing fluid field VTK output with OpenMPI version > 2.x.x

See merge request walberla/walberla!173

Added module description for pecoupling

See merge request walberla/walberla!172

- proper escaping of braces when passing JSON to python
- pass information if walberla was built with CUDA to pystencils
  to support apps that use GPU optionally

- allows for nested execution flow (i.e. solver loop inside time loop)
- timing tree integration
- parallel CUDA stream support

- WALBERLA_BUILD_WITH_OPENMP was never defined

Add forgotten incrementor in iterator macro

See merge request walberla/walberla!171

Fix typo in iterator macros

See merge request walberla/walberla!169

when compiling with undefined behaviour sanitizer and gcc 8.2
a -Werror=maybe-uninitialized warning appears when using the const refs
the std::move variant does not have this problem

Use for loops instead of while loops in iterator macros

See merge request walberla/walberla!168

- for example conda ships this old MPI version

Su Viscoelasticity

See merge request walberla/walberla!146