added WallModelProbe, replaced PostProcessingVariable with Statistic in Probe (and all derived classes) and added some documentation

Added SG model to StressBC, added Timer-class which wraps existing timer in Simulation, added round-off correction in TurbulentViscosityCumulantK17CompChim_Device (testing ongoing)

Fixed periodicity issue by addind STOPPER_OUT_OF_GRID_PERIODIC flag. Further preparaions for stress BC

Added configBoundaryLayer.txt. Added Slip BC allocations to GridGenerator. Can now be used again, but thus far ignores normals and uses the default q's set by the SideType. Modified NoSlip BC, now just adds a velocity BC with zero velocity.

adds wrapper for gpu WIP

(cherry picked from commit b3cf5c2eb5dad849b6c8d71552ca995fbe7a487e)

cherry-pick 56b49f3

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

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

Warning: [-Wbackslash-newline-escape]
https://stackoverflow.com/questions/31673945/clang-backslash-and-newline-separated-by-space-in-single-line-comment

Made VF_GPU work with the "new" cmake