Validation link for awarded badge action 

Event system for getting validation link for badge log.

When you see the list of badge you earned you can go further and click on one to see details of the awarding process.
On this page you got all the action that lead to the awarding listed.

Now you can define the link to the resource on which the action has been executed.
This link is here as a validation step, in addition to the rule system, and to show people what you have done (or what someone do to you).

The process to define this link is simple, you just need to create a listener that listen to event and return the link.
An example can be see in the [blog plugin](https://github.com/iCAPLyon1/BlogBundle/blob/master/Listener/BadgeListener.php#L33).

If you don't define this listener a try to guess a default link will be done.
For now just if the log has a resourceNodeId on it a link to this resource will be generated, and if not no link will be displayed.

Doc has been update