Add support for Live Reload

When preparing a presentation, it's quite handy to automatically reload the view in the browser when the content changes. I've enabled that with the Live Reload capability of the grunt-watch plugin (don't forget to run 'npm install' again).
just add livereload: true to the connect options and it will be automatically injected when running locally. That way it doesn't interfere with the presentation when running in 'non dev' environments.