Adding improved 64-bit hash functions.
Adding improved 64-bit hash functions.

I tested this by computing 1024^3 hashes of 4 randomly-generated input
keys. No collisions were detected.

Mbewu/libmesh,Mbewu/libmesh,Mbewu/libmesh,Mbewu/libmesh,Mbewu/libmesh,Mbewu/libmesh,Mbewu/libmesh,Mbewu/libmesh,Mbewu/libmesh