Remove leftovers from the git sample pre-commit hook that we don't
really need in this script.

Includes a short description, requirements, installation instructions,
testing information, and license information.

Remove all the conditions and code copied from Vcsh and only do the bare
minimum necessary to run tests. This will bork in more unexpected ways
if `git` or `prove` aren't present, but it allows us to get rid of the
only GPL-licensed code in the codebase, freeing me up to license the
project in any way I want.

* Add sample malformed JavaScript files to lint on
* In our tests, copy the `node_modules` directory to make `jshint`
  available, then validate that we're correctly linting the staged JS
  file
* In our pre-commit hook, lint the staged JavaScript files. If either of
  our linting commands fail then exit 1 to abort the commit.

Ensure we reset the staging area as a teardow/cleanup operation.
Otherwise, our JavaScript test (which runs after this one by default)
will be working with a dirty staging area and its test will by
consequence not pass.

One of our tests confirms that our 2 Python files are in the repo
directory. Since we're also adding JavaScript files to this directory,
we need to restrict the test to Python files in order to match them
correctly. In this case since we're only testing Python files we don't
really need to worry about the JS files' existence.

* Create a package.json with 'jshint' as a dev dependency
* .gitignore: Ignore node_modules because why not, and it only has dev
  dependencies in it.

Make it explicit that we depend on `flake8`.

Otherwise they'll fail since `flake8` won't be available.