cj4 log to file after first kernel run

cj4 array is written to file after the first kernel execution.

For the OpenCL version. the results are also compared to the CUDA
results, if the corresponding file is found.

OpenCL: see
#define DEBUG_DUMP_CJ4_OCL
Output files: ocl_cj4.txt

CUDA: see
#define DEBUG_DUMP_CJ4_CUDA
Output files: cuda_cj4.txt