Adds the specified database (via database meta-data) to the list of associated databases for
the transformation, or replaces the database if it already exists in the list
This servlet allows a client (TransSplitter in our case) to ask for a port number.
This port number will be allocated in such a way that the port number is unique for a given hostname.
This in turn will ensure that all the slaves will use valid port numbers, even if multiple slaves run on the same host.