Perf issues with large Flems (and assorted suggestions)

[pygy]

While writing vella, I reached a point where Flems became painfully slow. I know that it isn't meant for 1000+LOC demos, but I wonder if perf couldn't be improved by running lzstring on individual files, rather than on whole projects.

If you were to rethink the URL, another nice-to-have thing would be a slugified version of the Flems title in first position (and just ignore it when parsing, so that it can be amended after the fact).