Update session class and write session clas tester, update DB\IO Tester

DB\IO Tester now has correct testing for pgVersion string compare. Uses
mocked pgVersion return for this

Session class update with full magic set/get or method set/get for
_SESSION var. Also added full testing for this

www/lib/CoreLibs/DB/IO.php

@@ -1384,7 +1384,7 @@ class IO
 		// we only compare the first two
 		preg_match(
 			"/^(\d{1,})\.(\d{1,})\.?(\d{1,})?/",
-			$this->db_functions->__dbVersion(),
+			$this->dbVersion(),
 			$matches
 		);
 		$master = $matches[1];