Support for PAPE extension in the PZH Web Interface.

The PZH Web Interface now implements the OpenID Provider
Authentication Policy Extension (PAPE) and sets the maximum
authentication age to '0', requiring users to re-type their
password when logging into the PZH and preventing the
OpenID provider from caching authentication.

PAPE: http://openid.net/specs/openid-provider-authentication-policy-extension-1_0.html

Jira issue: WP-92
Merge pull request #467 from jplyle/WP-92-Pape-Extension

Support for PAPE extension in the PZH Web Interface.