Add graph attribute on StateMachine
Merge pull request #31 from winzou/graph

Add graph attribute on StateMachine
Add the ability to pass arguments to callbacks
Add a callback to ease the cascade of transitions
Adapt bundle configuration to accept arguments
Add CascadeTransitionCallback service for bundle
Fix typo in ArrayLoader
Use ExpressionLanguage for callback args

To be much more powerful and control each and every arguments to your
callbacks
Add CascadeTransitionCallback unit test