Master tweaks for folders

Here are a few tweaks to make it easier to maintain folders in a separate branch. I think they add value, in themselves, and will make other changes easier, not just folders.

I have some more changes in mind, but have to scope them out. I expect they'll be less trivial than those in this batch, so will make them separate.

(And, woo-hoo, github makes it easy to do a PR to the upstream branch! Should have figured, but nice to see.)