Adds a Dockerfile configuration
that allows straightforward running of linters with compatible versions
locally. This removes a ton of annoyance when trying to appease CI,
because many of the linter versions are quite old and difficult to
maintain locally.
I realize that people may not be thrilled to more ancillary tooling to
the repo, but I think this makes a lot of sense given the linter
versions listed in this container configuration are dictated by this
repo (within the CI configuration), so having these things live in
two separate places is a recipe for version mismatches.
Eventually we can likely just use this container on CI directly to avoid
any chance of inconsistencies between local dev experience and CI.
Mostly changes to remove src/univalue exceptions from the various linters,
and the required code changes to make them happy. As well as minor doc
changes.
This adds a brief help text to `git-subtree-check.sh` and adds and an
option to do a full remote check instead of having two different code
paths with a successful exit status. Also make it explicit that the CI
is not doing this.
