The authentication plugin provides generic user support for Catalyst apps.
It is the basis for both authentication (checking the user is who they
claim to be), and authorization (allowing the user to do what the system
authorises them to do).

Using authentication is split into two parts. A Store is used to actually
store the user information, and can store any amount of data related to the
user. Credentials are used to verify users, using information from the
store, given data from the frontend. A Credential and a Store are paired to
form a 'Realm'. A Catalyst application using the authentication framework
must have at least one realm, and may have several.

To implement authentication in a Catalyst application you need to add this
module, and specify at least one realm in the configuration.

Authentication data can also be stored in a session, if the application is
using the the Catalyst::Plugin::Session manpage module.

*NOTE* in version 0.10 of this module, the interface to this module
changed. Please see the /COMPATIBILITY ROUTINES manpage for more
information.