This module provides Access Control List style path protection, with
arbitrary rules for Catalyst applications. It operates only on the
Catalyst private namespace, at least at the moment.

The two hierarchies of actions and controllers in Catalyst are:
* Private Namespace
    Every action has its own private path. This path reflects the Perl
    namespaces the actions were born in, and the namespaces of their
    controllers.
* External Namespace
    Some actions are also directly accessible from the outside, via a URL.
    The private and external paths will be the same, if you are using
    Local actions. Alternatively Path, Regex, or Global can be used to
    specify a different external path for an action.

The ACL module currently only knows to exploit the private namespace. In
the future extensions may be made to support external namespaces as well.

When a path is visited, rules are tested one after the other, with the most
exact rule fitting the path first, and continuing up the path. Testing
continues until a rule explcitly allows or denies access.