* Made the PostgreSQL library a compile-time dependency (it used to be
runtime only as it was used as the JDBC driver, however it is now used
directly to access PostgreSQL-specific types; this does not matter, as
the DB code is already 100% specific to PostgreSQL)
Added a Maven project that will contain all resources-related
components. Updated list of children in the top-level components
project. Added dependency to the main project.