Add an Example for NguyenWidrow Class

[tdaug118]

Please add an example for NguyenWidrow Class.

TODO (optional): The methods include Randomize() that is described as using a Gaussian distribution, and Randomize(Int32) using Nguyen-Widrow methods. This sounds to me like Randomize() does not use the Nguyen-Widrow method. Is that true? What do I use for the Int32 argument in Randomize(Int32)?

Help Topic: http://accord-framework.net/docs/html/T_Accord_Neuro_NguyenWidrow.htm