- Moved all seed related scripts to contrib/seeds for consistency
- Updated `makeseeds.py` to handle IPv6 and onions, fix regular
expression for recent Bitcoin Core versions
- Fixed a bug in `generate-seeds.py` with regard to IPv6 parsing
This makes it possible for a node with `-onlynet=tor` to bootstrap
itself.
It also adds the base infrastructure for adding IPv6 seed nodes.
Also represent IPv4 fixed seed addresses in 16-byte format.