Attack of the 50-foot reposturgeon

Well, I thought I was done hacking on this for a while. Then one of the projects I did a conversion for disclosed the existence of a second repo for their website, which I had to merge into the code repo. As a subdirectory. Which meant pushing all the file paths into a subdirectory. Which meant the new “paths sub” command; I wrote “paths sup” as its natural dual.

Also in this release: automatic preservation of untracked files under git and hg.

Fear the reposturgeon!