Update dependencies / Fix .npmignore

* I updated the dependencies and devDependencies, then rebuilt the fies in the `dist` directory with Grunt.
* I updated `.npmignore`. The `node_modules` directory is ignored by default. See the npm developer guide,  [*Keeping files out of your package*](https://www.npmjs.org/doc/misc/npm-developers.html#Keeping-files-out-of-your-package).