The default build only retrieves dependencies that released under a license compatible
with the Apache Software Foundation. To optionally download the optional LGPL dependencies
and compile the dependent Struts code, run the 'compile-optional' task.
This task retrieves optional dependencies that are released under licenses that are
not endorsed by the Apache Software Foundation. In particular, these dependencies
use the LGPL license - http://opensource.org/licenses/lgpl-license.php