C99 translation of Geoff Pike's and Jyrki Alakuijala's CityHash.
This hash is superseded by FarmHash (see farmhash-c)
This version of CityHash is translated from the original code released via google code (1.1.1), and may differ from smhasher. For rough performance metrics, please see Reini Urban's smhasher fork.
The code is intended to be platform agnostic, excluding some compiler
intrinsics. However, please note byte swap and rotate right are used in the
hashes and platform optimized versions are not included, which may compromise
performance. Additionally, byte swap is necessary for big-endian
architectures.