OpenCL: Fix some header includes using brackets instead of quotes.
keyring-opencl: Optimize for 2.5x boost, add auto-tune, bump length limit.
OpenCL oldoffice & krb5pa-md5: Fix --test=0 (they failed because we
required an LWS of 64 - but we can do with anything up to 64).
Add auto-tune to pbkdf2-hmac-sha512-opencl.