Bug 9812 - Forbid access to several files through the browser

This patch hides (-Indexes) and forbids (Deny from all) access to some stuff through a browser.
Specifically "xlst", "modules" and "includes" dirs and its contents.

This is just a quick fix we talked about at IRC. The proper solution would be to remove this from htdocs which will still be needed.

Signed-off-by: Chris Cormack <chrisc@catalyst.net.nz>
Signed-off-by: Jonathan Druart <jonathan.druart@biblibre.com>
Signed-off-by: Chris Cormack <chrisc@catalyst.net.nz>