[WIP] Tutorial Updates for 1.2

Updates and improvements for 1.2.

Note there is a problem in that the RoutingAutoBundle intializes before the initializer that we create in the last chapter, causing it to fail.

We need to add support for initializer priority: https://github.com/doctrine/DoctrinePHPCRBundle/pull/173
I always miss this part and there was a user that got stuck with this too, so I have tried to make it a bit more obvious that you need to remove the old initialiser.