This non-deterministic behavior was showing only in the ARMv2a benchmark
around event 180k...
* Bug: In Anabatic::Session::_netInvalidateds & _netRevalidateds, the
set<> was still sorted on pointers. As contacts & segments can be
created to maintain connexity after a layer change, we got a
discrepency in objects Ids that may generate a change in ordering
later.
* Bug: In Katana::Session::_doRemovalEvents(), the set of Tracks that
got elements deleted was still using pointers. Now we use a TrackSet
sorted on (direction,depth,axis). This should not have created
a change in the results, as destructions do not change Ids, but it
genereate extra differences in traces.