added FWave OpenCl kernel
added missing calculation of u_l and u_r
Update OpenCL FWave implementation

The FWave kernel does no longer use a specified direction (x or y), but should be called from within other kernels. Also corrected handling of reflecting boundaries and improved formatting
Fix OpenCL Kernel compilation errors
OpenCL Kernel functions should not be inline
Fix speed calculation on dry-wet interfaces in OpenCL Kernel
Use #define for constant values
Allow to set OpenCL address space qualifier using preprocessor