Serve concatenated/minified/compressed css

There are countless reasons to stop serving a static css file using the @import statement. But because It drastically improves performance & allows us to run diagnostics on the theme is enough in my book.

We need some sort of way to merge/minify/compress the css that we serve on the fly. It should do this based on some sort of check of a db field with some sort of unique hash or maybe a timestamp.

Or we need to ship a merged and merged/minified version rather than one using @import.

I would also suggest that we split out the cp file as its own include for just those pages somehow.

Open to suggestions.

We should really consider extending this to the JS at some time as well, but the focus should be on the css which is more important.

Disscussion: https://area51.phpbb.com/phpBB/viewtopic.php?f=81&t=45669