Removing scroll & resize event listeners

[micahjon]

First of all, thanks for a great repo! I had no idea Disqus embeds bundled so much JS & CSS.

I noticed that scroll & resize event listeners aren't removed on Disqus initialization. I imagine the performance impact is minimal, but it'd still be best practice to remove them. If you'd like, I'd be happy to submit a PR.

[yowainwright]

I 2nd the thank you!