* Bug: In Hurricane, in Cell::flattenNets(), addition to the topHyperNets
vector was done *inside* the components loop, resulting in multiple
additions of the same top net. This was leading to the RoutingPads
created multiple times on the same connectors. Hence the conflict in
KiteEngine::protectRoutingPads().
* Change: In Hurricane, in Cell::flattenNets(), do not create RoutingPads
or build rings on already routed Nets. A Net is considered already
routed if it has at least one Segment. This way we avoid Rubbers to
be drawn over routed Nets.
* Change: In Hurricane, in DeepNet, do not build RoutingPads & rings on
already routed Nets (same condition as in Cell::flattenNets()).
* New: In Hurricane, in HyperNet, new collection of all component
occurrences of an HyperNet. May or may not (default) include
components from the leaf cells.