[ipv6calc] ipv6calc sources moved to GitHub

Hi,

I've moved the "ipv6calc" source code from DS6's "old" CVS to "modern" GitHub.

https://github.com/pbiering/ipv6calc

DS6 public CVS server and the Web2CVS interface will be closed down sometime in the near future.

Developing will be ongoing but the only demand so far from others is adding support for a different DB than Berkeley DB (because of license change) - current plan is use LMDB in the future - this will be implemented before the 1.0.0 "snowfall" release (don't expect it earlier...).

Regards, Peter