Rack aware test always has at least two nodes.
Generate and log new seed for every test iteration.
Delete uninteresting edges during dfs phase.

If we know that this edge didn't produce a valid path to the sink, it
won't the next time either. So every time we encounter such an edge,
we increment firstEdge. So the next time this edge won't be considered.
Increase MaxCounts.

maxflow is fast enough now to accommodate it.
Add some stats about graph.

Just for convenience. Those could be easily computed of course.
Add some stats about maximizing the flow.