* spec updates
* random small updates
* ssz no longer sorts by field, fix enum serialization
* rewire block processing a little to avoid a few state copies
* add a state simulation tool that writes out jsons
* ssz: finish implementation
* add object support, simplify implementation
* fix extra round of hashing in tree_hash_root
* ssz: cleanups
* work around Nim range bug for Uint24, cleanups