Implement persistent storage for Nutch Webserver resources

The Nutch webserver caches resources (seed lists, configuration, jobs, etc.) in-memory. This is not a reliable or resilient solution for users who want a persistent Nutch server service for the enterprise.
I therefore propose to add a persistence mechanism which will address this problem.
I intend to use JOOQ as a thin layer on top of JDBC. This will provide flexibility for deploying a wide variety of RDBMS backends.
h2 is a popular, very lightweight (~2.5 MB) appropriately-licensed solution we could use as the initial backend. I intend to use it in embedded mode with enabled persistence so we'll have data on the disk. This means that if we stop Nutch server we can restart and restore server resources from disk.

Some resources
https://www.jooq.org/
https://h2database.com/html/download.html
http://www.h2database.com/html/tutorial.html#using_jooq