Tokens are generated differently

[jessepeterson]

For both the Tokens and Declaration Items endpoints we generate the tokens by iteratively building and hashing them within Go. However ServerTokens for the Declarations themselves are all stored and managed in MySQL. This dichotomy of different approaches is a little odd. This was done to reduce complexity in the storage backend as well as to try and reduce race conditions in MySQL by avoiding a separate query using, say, GROUP_CONCAT() to hash the individual declaration tokens. As well we wanted it to be really fast. So we use a non-cryptographic hashing function called xxhash. This may not have been a good approach by splitting these.