* The main loader script has been updated to generate the list of files
it needs to load automatically. As a consequence, files that contained
manually-maintained lists of scripts have been removed, and definition
directories have been renamed accordingly.
* PostgreSQL extension loading and configuration has been moved to a
separate script to be loaded automatically in the main transaction.
* Data and function definition scripts that had the -data or -functions
suffix have been renamed (the suffix is unnecessary).
* Unit tests have been reorganised to follow the definition's structure.
* Documentation has been improved
* Fixed privileges on both variants of defs.uoc_natural_resource()
* Added user unit tests which check execution privileges on all (new)
stored procedures and INSERT/UPDATE/SELECT/DELETE privileges on all
(new) tables
