Remove backwards compatibility code on next major version release

[ethack]

This issue is a catch-all for code that is only used to maintain backwards compatibility and can likely be removed the next time we have a good reason to release a new major version and thus break backwards compatibility.

• MetaDB config entry. Pull request. Specific commit to remove.

[carrohan]

@ethack is "MetaDB config entry" also supposed to be a link, or is it just the title for that bullet?

[ethack]

I think it's just a title and not supposed to be a link. But we need to hold off on this issue until we're ready to break backwards compatibility (i.e. release v4). So don't work on this one quite yet because I don't think we're at that point yet.