Bug 17486: Remove Mozilla Persona

Bug 17486: Remove Mozilla Persona

Persona never really took off, and although many browsers currently
support it, very few services actually implement it.

This has lead to it's founders, Mozilla, to end the project. In their
own words:

=============================================================================
Persona is no longer actively developed by Mozilla. Mozilla has
committed to operational and security support of the persona.org
services until November 30th, 2016.

On November 30th, 2016, Mozilla will shut down the persona.org services.
Persona.org and related domains will be taken offline.

If you run a website that relies on Persona, you need to implement an
alternative login solution for your users before this date.

For more information, see this guide to migrating your site away from
Persona:

https://wiki.mozilla.org/Identity/Persona_Shutdown_Guidelines_for_Reliers

=============================================================================

Given the above, and that the Persona authentication methods as a whole
are no longer being actively maintained by anyone anywhere to ensure
ongoing security, we should deprecate the option from koha.

Test plan:
Apply this patch and make sure you do not find any references of Persona
Have a look at patches from bug 9587 and confirm that everything has
been reverted

Signed-off-by: Owen Leonard <oleonard@myacpl.org>
Signed-off-by: Marcel de Rooy <m.de.rooy@rijksmuseum.nl>
Code looks good to me.
Also ran several tests including: Auth.t, Auth_with_shibboleth.t.

Signed-off-by: Kyle M Hall <kyle@bywatersolutions.com>