Support UPDATE/DELETE/INSERT based on Query Name

This is a proposal on how to handle the execution of so-far-unsupported DELETE/INSERT/UPDATE queries. I suggest to decide on the usage of either `clojure.java.jdbc/query` (for SELECT) or `clojure.java.jdbc/execute!` (for everything that changes data) by analyzing the query name: If it ends in an exclamation mark (`!`) use `execute!`.

Also, this enables the generation of the raw query vector by omitting the DB configuration parameter when calling the query function, making #4 obsolete.