[#217]Add Tuple.function[N]

[TRebirthC]

This is the inverse operation for [issue:#214].

[lukaseder]

Thanks for your suggestion. I'm not in a hurry to add these methods as mentioned in #217

I'd like to gather feedback on the utility of them first, and then still perhaps decide that we don't need them.

Please discuss your suggestions first before engaging in working on them, there's always a risk of doing unnecessary work (notice also, we have a code generator to generate the API for 1-16 overloads! I hope you didn't do all of this manually?)