Feature: Added simple logging singleton that is designed to be overwritten so that it can be integrated into other code easily
Chore: Updated rake to latest version
Feature: Added debug logging code into Coordinator, and XMPP channel
Fix: SubscriptionList will now allow backeneds that previously connected to a subscription to be retried
Feature: XMPP channel will now trigger failure callbacks for pending subscriptions
Chore: Switched to https for rubygems Gemfile