Grunt, Gulp, Webpack 2 or something else?

[jayands]

I'd like your opinion on the matter. In the original source code, Grunt is referenced in the comments. However, I like both Grunt and Webpack, with WP2 being just a little higher.

I kind of get Gulp, but it's more a fault of mine than theirs, as I have properly configured it before. To me, though, it doesn't feel quite right. Of course, I'd like your opinions on the matter, as well as pull requests being open.