Various OpenCL formats: Use byte addressed stores if allowed (though
sometimes not if AMD). For RAR this gave 33% boost on AMD.
raw-sha512-opencl: Obey device/kernel limit for LWS.
Merge branch 'bleeding-jumbo' into memdbg

* bleeding-jumbo:
  raw-sha512-opencl: Obey device/kernel limit for LWS.
  Various OpenCL formats: Use byte addressed stores if allowed (though sometimes not if AMD). For RAR this gave 33% boost on AMD.