Revert "Convert DB class into an alias of Rhymix\Framework\DB, instead of extending it"

This reverts commit 9d3b5924e9.

classes/db/DB.class.php

@@ -1,3 +1,6 @@
 <?php
 
-class_alias('Rhymix\Framework\DB', 'DB');
+class DB extends Rhymix\Framework\DB
+{
+	
+}