Fix whitespace view in code

[thesayfulla]

Fixes #2041

[tim-schilling]

Thank you @thesayfulla for pushing this forward. I updated your approach quite a bit. Let me know what you think. The whitespace wasn't being respected in my testing until I adjusted the .w class styles to use white-space: pre-wrap.

I took it a step further and regenerated the pygments styles so that we get the color highlighting too.

@matthiask I think this is how the toolbar used to do things, but I suspect some of the details were lost to time.

[matthiask]

Thanks, that's excellent!

[tim-schilling]

@thesayfulla if you're good with the result, we can merge this in.

[thesayfulla]

@tim-schilling Great job! I really liked it - let's move ahead and merge it.