Moved GKS stuff - Not tested!

src/gpu/GksGpu/BoundaryConditions/BoundaryCondition.cpp

src/gpu/GksGpu/BoundaryConditions/BoundaryCondition.h

src/gpu/GksGpu/BoundaryConditions/ConcreteHeatFlux.cu

src/gpu/GksGpu/BoundaryConditions/ConcreteHeatFlux.h

src/gpu/GksGpu/BoundaryConditions/CreepingMassFlux.cu

src/gpu/GksGpu/BoundaryConditions/CreepingMassFlux.h

src/gpu/GksGpu/BoundaryConditions/Extrapolation.cu

src/gpu/GksGpu/BoundaryConditions/Extrapolation.h

src/gpu/GksGpu/BoundaryConditions/HeatFlux.cu

src/gpu/GksGpu/BoundaryConditions/HeatFlux.h

src/gpu/GksGpu/BoundaryConditions/Inflow.cu

src/gpu/GksGpu/BoundaryConditions/Inflow.h

src/gpu/GksGpu/BoundaryConditions/InflowComplete.cu

src/gpu/GksGpu/BoundaryConditions/InflowComplete.h

src/gpu/GksGpu/BoundaryConditions/IsothermalWall.cu

src/gpu/GksGpu/BoundaryConditions/IsothermalWall.h

src/gpu/GksGpu/BoundaryConditions/MassCompensation.cu

src/gpu/GksGpu/BoundaryConditions/MassCompensation.h

src/gpu/GksGpu/BoundaryConditions/Open.cu

src/gpu/GksGpu/BoundaryConditions/Open.h