Due to exploits found in KGW, I've implemented a new difficulty retargeting algorithm called DarkGravityWave.

What is DarkGravityWave? It uses multiple exponential moving averages and a simple moving average to smoothly adjust the difficulty. This implementation is far more simplistic and better suited to adjust difficulty than KGW and also fixes all known exploits.

Here's the commit if you're interested:

https://github.com/evan82/darkcoin/commit/07c99052edc617975cdcbe4482e02c52e2d1fbf5