API for using ArraySlice

[AndrewLipscomb]

For my work I needed to keep array copies at a minimum (dealing with arrays with 100s of 1000s of points) and modified the code here to include an ArraySlice API for dealing with large subsets of the big arrays

Any interest in a pull request for that API? I wasn't sure how to handle the highestQuality parameter - in my use case I took it out to prevent an array copy but I think the simplifyRadialDistance method could be overloaded to slice the input array even thinner.

[malcommac]

I think it's an interesting addition if you want. Let me know I'll merge it ASAP.