0.1.9 "Now More Normal"

This release changes the GWT inherits to ones that reliably work (this actually happened in 0.1.8), and improves the quality/range of normal-distributed values produced by Ziggurat. There was a subtle "jog" in the graph of normal-distributed values in 0.1.8 and some earlier versions, where in the "trail" of the most extreme-magnitude values, the start of the trail had a cluster of unusually-frequent values and then suddenly dropped back to normal. There was also some sort of bias in how high-magnitude Ziggurat could produce positive numbers compared to negative ones, and positive values were able to be higher. Now both positive and negative numbers can have higher magnitudes than before (a sign that it's approximating the trail better), and the "jog" is gone. Ziggurat probably isn't quite as fast now when the problematic cases occur (less than 0.4% of the time), but the rest of the time, it should be comparable.

See the README.md for the different GWT instructions.