Also add a makefile. This will need a cherrypick onto 1.0,1.1
with edits to hack/jenkins/test-dockerized.sh to run branch-specific
test scripts.

Also had to modify hack/verify-api-reference.sh to handle volume mount
path peculiarity when doing `docker run -v` inside a container started
with `docker run -v`. See associated comment in
hack/jenkins/test-dockerized.sh