* New: In Anabatic::EdgeCapacity, dedicated object to manage the capacities
of an edge by layer. This needed now because with real technologies
layers capacities differs (unlike with symbolic technologies).
This object is separated to be shared between Edges with identical
characteristics (direction+interval). Deletion is automatic and
done through refcounting. All the already allocateds EdgeCapacity
are kept into a set in the AnabaticEngine (key is (direction,interval)).
* New: In Anabatic::Edge, capacities are stored in a shared EdgeCapacity
object. The total capacity can be annotated (i.e. decreased).
EdgeCapacity attribute is created during the materialize() call.
The capacities are computed at this time.
The incCapacity() function is renamed in reserveCapacity().
* New: In Anabatic::AnabaticEngine, added attribute _edgeCapacitiesLut
to store the shared EdgeCapacity.
Lookup/Creation of an EdgeCapacity is done through _createCapacity().
* Change: In Anabatic::Constants, rename Flags::IllimitedCapacity into
Flags::InfiniteCapacity. Add Flags::NullCapacity (both for Edges).
* Change: In Anabatic::GCell, implement a by depth (for layer) getCapacity().
This modification did expose a bug in the density calculation :
per depth density where divided by the complete density instead of the
density's depth. This was leading to greatly underestimated densities.
Thoses underestimations where preventing Dijkstra and layer assignement
to manage congestion correctly (in fact, it was acting as if there
never was congestion).
Also avoid a divide by zero (thus -NAN showing in densities).
* Change: In Anabatic::GCell, rename setEdgeOccupancy() into the more
accurate forceEdgesCapacities().
Note for Eric: only the first Edge on each side has it's capacity
forced. What if there's more than one Edge ?