Refactored with some clojure branch design ideas.
Example schema updates.

Renamed artists.name_jp column to real_name.
Added missing publisher column to albums table.
Refactor to use models instead of plain arrays.

Added a Service layer to map db results to models.
Models will now partially populate themselves in their constructors from db results.
Removed Entity and Listing sub-packages from the Model namespace.
TODO: consider ORM mapping.