* First pass at iterative siphash
* Generalizing our siphash24 implementation slightly to make it friendlier to repeated hashing
* Block siphash algorithm, Cuckaroo placeholder
* Cuckaroo validator, still needs to be tested with vectors from the @tromp implementation
* Working cuckaroo validation with test vectors for cuckaroo19, will add cuckaroo29 vectors when a lean or mean implementation can find some solutions
