Add a new stddev_scaling_factor setting.
Users can now influence the width of the Gaussian distribution function, using a new stddev_scaling_factor setting. This allows the user to adjust how strongly the algoithm will prefer items at the top of the list over items at the bottom of the list. A larger number will give items at the top of the list a stronger chance of being chosen.
The setting is optional, defaulting to 3.0.
Signed-off-by: Randy Barlow email@example.com