Log contents of session when checking auth.
Log entry when clearing session and re-directing.
Log contents of params when checking auth.
Logging the session contents when redirecting away from the Facebook callback
Merge pull request #27 from nufyoot/more-logging

Logging the session contents when redirecting away from the Facebook
Remove extra Facebook user data from session to prevent session cookie size exceeding 4K and content being dropped. Fixes #28.