Add support for Elliptic Curves of Genus n (Hyperelliptic Curves)

[Neo-Desktop]

Hello there,

Thank you very much for providing support for this open source project.

One project I'm currently working on currently uses Crypto++ and has a need for performing mathematical operations on Hyperelliptic Curves (specifically genus 2).

While libraries such as libg2hec exist, they depend on NTL which, when using Crypto++ for the rest of the application, seems a bit silly to include.

I'm not sure if support for this in Crypto++ was ever discussed in the past (a cursory google search didn't reveal anything), but I figure having an open ticket on GitHub may be the best course of action for both feedback and discussion.

Thank you again