CalculationFunction.m: Move OpenCL prologue into OpenCL.m
CalculationFunction.m: Move OpenCL epilogue to OpenCL.m
CalculationFunction.m: Move Stringify call for OpenCL into OpenCL.m
Vectorisation.m: Move OpenCLLocalsToGridFunctions to OpenCL.m
Move OpenCL include files to OpenCL.m
Thorn.m: Move OpenCL capabilities to OpenCL.m
KrancThorn.m: Process OpenCL differencing header in OpenCL.m