title: Is there any sort of "pre login" event or similar?
body: <p>I need to run some code prior to checking if a user's credentials are correct. Currently I'm achieving this with a custom event listener that fires on the <code>kernel.request</code> event and checks if the requested URL matches security.yml's <code>check_path</code> setting. But this is inefficient since it runs on every request. I'm aware of the <code>onSecurityInteractiveLogin</code> event, but I believe that fires after a successful login attempt.  Does anyone know if there's a pre login event, or where I could dispatch a custom event myself?</p>