Implements pressure and stress correction for multiphase model with density contrast. Pressure is regularized and hence different from the form used by Safari and Fakahri. Surface tension is not implemented.

Implements cumulant phase field function and a passive incompressible momentum equation. The phase field is only coupled to the fluid velocity but there is no featback to the fluid. Only as a starting step for further developments.

Fix various msvc compiler warnings. With msvc the compiler flags are explicit passed to nvcc with -Xcompiler.

As thrust is used in the gpu code, CUDA c++14 is required. Besides fixed compiler warnings in Parameter.cpp.

Remove some compiler warnings and added some cuda warning suppressions for the GridGenerator, as they are cluttering the build output.