* Bug: In Knik, in Vertex the _flags attribute was unitialized.
This flag is, in particular, telling if the vertex is blocked.
That it was taking a random value, was leading to errors and
unreproductible behaviors. I hope this will make the global
router deterministic at last. This problem did show in the
Stratus FIFO generator.
* Bug: In Knik, in Vertex, remove the unused _boundingBox attribute.