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.