excalibur: Detects whether a config file is acl or not and acts accordingly.

Signed-off-by: Martin Stone <martin@d7415.co.uk>
arthur.wsgi: Changed path to match the rest of the branch.

Signed-off-by: Martin Stone <martin@d7415.co.uk>
excalibur: acl and legacy store "reqexpire" in difference sections.

Signed-off-by: Martin Stone <martin@d7415.co.uk>