Merge pull request #159 from Sayantan2048/unstable-jumbo

des-opencl:fixed detection of matching salt
Drop UTF-8 test from Markov. The performance impact is not worth it. For slow
formats we could use an external filter.
OpenCL crypt-md5: Get rid of global memory use in inner loop. More effective
buffer use and some other tweaks. Significant boost on both nvidia and AMD.
A few more md5crypt-opencl tweaks, mostly cosmetical.
des-opencl:hardcoded kernel