- LB on GPU, Uniform Grid Benchmark app
- helper class to schedule tasks to multiple CUDA streams

- comparison to old CPU transfer communication included

- CUDA compiler has problems to compile external json library
- timing pool is included by BlockForest, and previously timing pool
  included JSON library

previously the ghost layer was aligned

Features:
   - uses generated pack infos for packing & unpacking directly on GPU
   - can directly send GPU buffers if cuda-enabled MPI is available,
     otherwise the packed buffers are transfered to CPU first
   - communication hiding with cuda streams: communication can be run
     asynchronously - especially useful when compute kernel is also
     split up into inner and outer part

- added RAII classes for CUDA streams and events
- equivalence test that checks if generated CPU and GPU (overlapped)
  versions are computing same result as normal waLBerla LBM kernel

- templated buffer classes allow the buffer systems to work with custom
  buffers, e.g. buffers of GPU memory

Fix for numerical issue in EPA

See merge request !154

Add waLBerla-conforming .editorconfig

See merge request !156

Change stringstream name in macros to hopefully avoid name clashes

See merge request !155

Resolve "add sent and received bytes to BufferSystem"

Closes #75

See merge request !153

integrated g++8

See merge request !150

extended OpenMPWrapper with runtime functions

See merge request !149

Resolve "Segfaults with OpenMPI 2.1.1"

Closes #73

See merge request !148

Add missing inline in KernelFieldInterpolator

See merge request !147

Dirichlet and Neumann boundaries for PDE module

See merge request !105

Functionality for Adaptive Mesh Refinement and Load Balancing with pe coupling

See merge request !121