Initial import of tasks application

This initial import is a heavily modified version of the code I had
here, as Arse was modified for other purposes in the meantime and the
application no longer worked with it.

In addition:
 * I did not import the user management part yet,
 * task dependencies are supported in-base, but there is no interface
for that yet.

includes/t-items/pages.inc.php

@@ -0,0 +1,19 @@
+<?php
+
+class Page_TasksItems
+	extends AuthenticatedPage
+{
+
+	public function __construct()
+	{
+		parent::__construct( array(
+			''		=> 'items_tree' ,
+			'view'		=> 'view_item' ,
+			'add'		=> 'add_item_form' ,
+			'move'		=> 'move_item_form' ,
+			'edit'		=> 'edit_item_form' ,
+			'delete'	=> 'delete_item_form' ,
+		) );
+	}
+
+}