wyhash has very good performance for small keys (our usecase) and works on platforms with alignment concerns. A user had an issue where fasthash64 lead to misaligned reads and signal exceptions. wyhash does not have such issues and is faster.
Does not enable READDIR_AUTO. Might add in the future.
Use fasthash64 to hash filenames to uint64_t and store in khash set. Significantly reduces malloc/free'ing and memory usage.
