Add JDBC db server support

[christophd]

Database server connectivity causes severe pain in integration testing. We should be able to simulate a JDBC database server that acts as any database. The server receives database operations such as openConnection(), createStatement(), executeQuery(), executeUpdate(). The JDBC server accepts those requests and simulates proper responses without storing any physical data. SQL queries such as SELECT, INSERT, UPDATE, DELETE are provided with proper result sets. CREATE or DROP TABLE statements are validated but do not add any table data at all.