The template loaders loads templates from a base directory (and can
optionally use a suffix). For example
$templateLoader = new PHPParser_TemplateLoader(
$parser, './templates', '.php'
);
// loads ./templates/TestTemplate.php
$templateLoader->load('TestTemplate');
Again the implementation is not optimal. The loader probably shouldn't
intantiate the Template itself, but instead should accept a
TemplateFactory. This seemed like overkill to me, so I left it out.