[patch] Tweak breakdown chance calculation algorithm

[EarthlingKira]

This patch changes 3 things:

First, and this is important: Reduced breakdown chance actually does NOT reduce breakdown chance AT ALL for vehicles with 100% reliability and ships with >= 60% reliability. Furthermore - and this is even worse - it makes a vehicle with 60% reliability and one with 100% reliability the same.... So I've fixed it so that reduced breakdown chance actually reduces the breakdown chance (accumulation) rate for all vehicles, always.


Second, I've also reduced the variance of the random breakdown hits for reduced vehicle breakdown setting so that it's a little more predictable


Third, and finally, reliability now actually really decreases the breakdown chance itself after enough breakdown rate was accumulated! I'm using reliability as a value to calculate the chance against the accumulated breakdown rate.


My rationale for this patch (and not using existing patches) was that I did not want a big overhaul of the breakdown system, this is still the old system just with some small tweaks which greatly improve enjoyability of the system.