Added vim *.swp files to gitignore.
Support for lint.

Added jshint as a dev dependency and a "lint" script. `npm run-script
lint` will do it. Included a reasonable jshint config file.
Style fixes to eliminate lint errors.
Mocha Unit Testing.

Upgraded unit test to use Mocha. Expanded on the test itself. Modified
lint config to avoid choking on Mocha globals. Set npm test script and
set lint to run pre-test.