Removes pointless error utility function
Renames util.js to crypto.js
Migrates all usage of crypto-js/sha256 to ./crypto
Adds tests and fixtures for ./crypto
Hash160 now outputs a buffer
Changes deepEqual to equal
Adds magicHash test vectors and removes convert
Adds better ECDSA test vectors for recoverPubKey
Removes unnecessary ECDSA functions, moves compact signatures to Message