Implement a delegating LoginModule

[hzbarcea]

There is already a TokenLoginModule, but that is configured to use local files for storing public keys. Another option is to use a remote service, either via an API (http) or, even better, using a JMS queue to a remote service/consumer.

The Login module should be configured with the public key(s) of the remote service and the remote service should sign the response for enhanced security.