- renamed the mpi module to parallel
- removed the communicationRoutine interface from gpu. gpu now also uses the communicator interface from parallel
- added missing functionality in parallel/Communicator
- moved ws2_32 library dependency on windows from VirtualFluids_GPU to parallel

They are part of a future merge

We want to be able to control the time loop from the outside. This is needed for the coupling to Kratos Multiphysics for FSI

Renaming Conc to concentration and distributionAD27 to distributionAD (the first one fixed a bug BTW)
+ some reordering in parameter.h

Related to #37