Database definition & tests organisation

* 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

legacyworlds-server-data/db-structure/tests/user/030-data/100-universe/010-verse-resource-providers.sql

@@ -0,0 +1,28 @@
+/*
+ * Test privileges on verse.resource_providers
+ */
+BEGIN;
+	SELECT plan( 4 );
+	
+	SELECT diag_test_name( 'verse.resource_providers - INSERT privileges' );
+	SELECT throws_ok(
+		$$ INSERT INTO verse.resource_providers( resource_name_id ) VALUES ( 1 ); $$ ,
+		42501 );
+
+	SELECT diag_test_name( 'verse.resource_providers - UPDATE privileges' );
+	SELECT throws_ok(
+		$$ UPDATE verse.resource_providers SET resprov_quantity = 42; $$ ,
+		42501 );
+
+	SELECT diag_test_name( 'verse.resource_providers - SELECT privileges' );
+	SELECT throws_ok(
+		$$ SELECT * FROM verse.resource_providers; $$ ,
+		42501 );
+
+	SELECT diag_test_name( 'verse.resource_providers - DELETE privileges' );
+	SELECT throws_ok(
+		$$ DELETE FROM verse.resource_providers; $$ ,
+		42501 );
+
+	SELECT * FROM finish( );
+ROLLBACK;