Move front-end tests to separate files.
Add Gruntfile, package.json to prepare for modules.
Move front-end files into modules.

Grunt is used to concatenate the files together. The output file is
located in dist/mongoWebShell.js.
Move spec files to spec/mws/ to match src/mws/.
Add "grunt watch" task to rebuild dist/.
Add development Procfile.

This runs the front-end compile tasks in addition to the web server.
Add .env.sample.
Update README with frontend build info.
Merge pull request #123 from mcomella/modules

Move front-end code into separate files