Create a webpack DLL new sample under misc

[brauliodiez]

Webpack DLL is really cool, and can make your build process 10 times faster.

Let's build a sample for this.

Good material to learn more about this:

https://medium.com/@soederpop/webpack-plugins-been-we-been-keepin-on-the-dll-cdfdd6cb8cd7#.4wrtx2o0l

https://robertknight.github.io/posts/webpack-dll-plugins/

http://engineering.invisionapp.com/post/optimizing-webpack/

[brauliodiez]

Completed and merged