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.

site/index.php

@@ -0,0 +1,8 @@
+<?php
+
+include ( '../arse/includes/loader.inc.php' );
+Loader::AddPath( dirname( __FILE__ ) . '/../includes' );
+Loader::Create( 'URLMapper' , 'tasks' )->fromPathInfo( );
+
+
+?>