Added a configuration option to disable OpenID.

If $config['openid']['enabled'] is set to false, OpenID is removed from
the navigation and direct accesses to OpenID login pages redirect to the
login page.

If OpenID is enabled, $config['site']['openidonly'] is ignored, i.e.
OpenID is required to go OpenID-only.

config.php.sample

@@ -99,6 +99,9 @@ $config['sphinx']['port'] = 3312;
 // $config['xmpp']['public'][] = 'someindexer@example.net';
 // $config['xmpp']['debug'] = false;
 
+// Disable OpenID
+// $config['openid']['enabled'] = false;
+
 // Turn off invites
 // $config['invite']['enabled'] = false;