* Added a set of tables which define game updates and their targets.
These definitions replace the old enumerate type. Added a set of
triggers which automatically create specific update tables, insert
missing entries, etc... when game update types are being manipulated.
* Removed manual insertion of game updates from empire creation
function and universe generator.
* Added registration of core update targets (i.e. planets and empires),
updated all existing game update processing functions and added type
registrations
* Created Maven project for game updates control components, moved
existing components from the -simple project, rewritten most of what
they contained, added new components for server-side update batch
processing
* 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.
