Packaging up the initial release.
Everything builds and all tests pass (including the docker containers), at least on my server.
Known Issues
The Makefile for the containers/... does not currently know how to construct the docker volume directories that the containers need for bind-mounting. This means that these containers can be built, but testing will fail on any servers that don't have these directories all pre-populated with all their permissions and ownerships carefully arranged (which is complicated when uid namespace mapping is enabled in Docker). For details, see the "current status" section in README-containers.md
For this reason, the top-level Makefile does not automatically descend into the ./containers subdirectory unless $BUILD_DOCKER_CONTAINERS=1.