debug build to load golstats.txt
started CudaBackend
added core/cuda_util.h for error checking
work on basic kernels
worked on CudaBackend, set and calcDMap.
not tested yet.
reduction of dmap to best match remains to be done.
CudaBackend basically working.
Thread usage and speed needs to be finetuned...
common abstract Backend class, started CpuBackend
cuda and cpu backend on same level. started benchmarking