[Autolayout] Bug with cycles and delays having mutual getter/setter

[ahonorat]

The autolayout throws an error when generating the diagram corresponding to the attached .pi.
BugAutoLayoutDelay_issue128.zip
In this tricky example, two actor forms a cycle: A0 <-> A0_bis. On both edges, there is a delay whose getter and setter are the delay on the other edge.

The error is generated by the method layoutFifos in the class AutoLayoutFeature. When fixing this bug, the new class HeuristicLoopBreakingDelays should be used instead of the classFifoCycleDetector in order to break cycles.

[antoine-morvan]

See also #83