Compressor-esque template tag

[markfinger]

Need to gut compressor's {% compress %} so that it can pull assets

Rather than relying on compressor's per-file processing, the assets need to be combined so that source maps can be preserved.

CSS assets can be fed directly into webpack

JS assets will probably require some fiddling. There are far too many shitty plugins that rely on an implicit global. Might need to add an endpoint on the build server

[markfinger]

Have explored this a bit and got a prototype working, but it feels like it should be handled downstream.

Primary motivation was improved source maps, but it looks like this is possible with compressor.

django-compressor/django-compressor#438
http://roverdotcom.github.io/blog/2014/05/28/javascript-error-reporting-with-source-maps-in-django/
https://github.com/roverdotcom/django-compressor-sourcemaps/