Query quota and rate limit info

For block quotas, there are a number of queries that are bought, with all, or a subset, of that number “split” off for a particular API key; e.g. a split is an allocation from the amount of queries purchased. Block quotas have a specific number of queries split with an expiration time (the expiration time is usually much longer than a day). For each API key, the DNSDB API server tracks the number of queries split, number used, and the expiration time. The number of queries bought is not visible to the DNSDB API server.