Crash on storage overhead of 0 for twitter dataset tests

[Xanhou]

While running the experimental setup for different amounts of query templates, I also experimented with the storage overhead. Setting it to 0 resulted in a crashed that was caused by an invalid partitioning coming from the Non-Overlapping heuristic. This is invalid behaviour, as a this simply indicates that the only valid partitioning is a single partition.

I tested this with different experimental setups and the issue seems to be based on a randomized input, since it is inconsistent in its behaviour. The Heuristic itself will also return without issue, propagating the error elsewhere, causing different error messages to be shown.

To reproduce:

1. Enable the VsTimeDeltaBFS (or any other experimental setup) in code/simulation/src/intergdb/simulationMain.ccp .
2. Set the storage overhead constant to 0.0. This constant is declared locally in the VsTimeDeltaBFS::process() method implementation. (Or process method of your setup of choice.)
3. Run the simulation a few times. I got 'lucky' almost every run.

[bgedik]

Why don't you post a pull request for a fix?