add t1ha (Fast Positive Hash)

[erthink]

Fast Positive Hash - just the fastest portable hash function.

Briefly, it is a portable 64-bit hash function:

1. Intended for 64-bit little-endian platforms, predominantly for Elbrus and x86_64, but portable and without penalties it can run on any 64-bit CPU.
2. In most cases up to 15% faster than StadtX hash, xxHash, mum-hash, metro-hash, etc. and all others portable hash-functions (which do not use specific hardware tricks).
3. Provides a set of terraced hash functions.
4. Currently not suitable for cryptography.
5. Licensed under Zlib License.

[brandondahler]

Have added this to my "to-do eventually" list.