Div-check optimizations + statistics fix.

Now, the loop that checks whether each path is diverse before adding it
terminates early if it finds enough new edges, so it doesn’t bother
actually calculating the diversity of each path. If zero diverse edges
were found, it checks whether the path is exactly identical to any
previously stored path.
I also fixed a glitch in the memory measurement: modValue was being
calculated using n/numReadings instead of nk/numReadings.