slice, concat fail

[Hypercubed]

I think you need to add shims for slice, splice, and concat. Currently they do not function at all much less return a PowerArray.

[techfort]

Thanks for that, will address it today.

[techfort]

I added an initial slice and splice implementation just for initial support. I will now investigate if there are any performance improvements that can be applied to it, so I will leave the issue open till I deem max performance is reached.