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.
Merge branch 'unstable-jumbo' into bleeding-jumbo

* unstable-jumbo:
  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.