opencl: Add a simple "fullheader" kernel interface
Keccak: Import algorithm code as-is
keccak: Adapt for BFGMiner
opencl: Add Keccak support via "fullheader" kernel interface
opencl/keccak: Unroll all the hash rounds properly
opencl/keccak: Add non-goffset support
Travis: Update with Keccak
Keccak: Include support in various builds
keccak: Adapt opencl intensity interpretation to have approximately the same desktop interactivity affect as SHA256d
Keccak: Simplify keccak_hash_data