Merge branch 'feature/distributed_particles' into develop

bfps/NavierStokes.py

bfps/_fluid_base.py

bfps/cpp/distributed_particles.cpp

bfps/cpp/distributed_particles.hpp

bfps/cpp/fluid_solver_base.cpp

bfps/cpp/fluid_solver_base.hpp

bfps/cpp/interpolator.cpp

bfps/cpp/interpolator.hpp

bfps/cpp/interpolator_base.cpp

bfps/cpp/interpolator_base.hpp

bfps/cpp/particles.cpp

bfps/cpp/particles.hpp

bfps/cpp/particles_base.cpp

bfps/cpp/particles_base.hpp

bfps/cpp/rFFTW_interpolator.cpp

bfps/cpp/rFFTW_interpolator.hpp

bfps/cpp/rFFTW_particles.cpp

documentation/_static/cpp.rst

documentation/index.rst

setup.py