Support OpenIDC authentication
    
    Similar with Kerberos authentication, authentication is done by
    mod_auth_openidc in Apache. Client must request protected resources by
    passing token got from Fedora OpenIDC. After succeeding to
    authenticate, ODCS will get chance to create new user for the client or
    just query existing one from database. Then, authorization can be in
    protected resource view methods based on FAS groups.
    
    Major changes:
    
    * Configuration of openidc is added.
    * httpd configuration for mod_auth_openidc is added.
    * method to create or load users and FAS groups.