Refactor dependencies AX - Persona

Issue Summary

Now:

OpenID provider AX implements hook_openid_provider() and processes on $op = 'response'. It then does some aliasing and parsing and calls openid_provider_persona_process_ax() to let openid_provider_persona retrieve attributes.

openid_provider_persona_process_ax() in turn invokes hook_openid_provider_ax() to let other modules add their information.

Problems:

* No clean seperation between UI and API - can't use provider persona without using its UI
* hook_openid_provider_ax invoked from hook_openid_provider_persona
* Modules that only want to use AX features need to use AX and persona because AX requires persona.

I e. g. would like to use simple content_profile profiles and plug them into AX.

Suggested solution

• Make AX independent from. Persona depends on ax.
• openid_provider_ax_response_process() invokes hook_openid_provider_ax()
• openid_provider_persona implements openid_provider_ax()
• openid_provider_persona_schema_definitions() moves to openid_provider_ax.module

Would that make sense? Am I missing something here?

Aside and may be related: does persona negotiation work? I've installed and tried provider/ax/persona, created 2 personas and the system never asked me which persona I'd like to use when I used my provider to create an account on the relying site...