Add more features

[peter279k]

As title, I need the sqrt, gcd and the logical operators(and, or and xor) with the big integer. Can I implement this features? How to set these method name?

Thanks.

[waltertamboer]

Hi @peter279k

I think it's best if you make a PR. We can discuss further in the specific PR. I'm sure changing names won't be the most difficult thing later on :)