This code is copied straight from the upstream Xpra client code, but with prettier formatting applied.
I couldn't find any npm modules that worked in the browser and actually decompressed xpra's lz4 compressed data. This does so and works VERY well/fast. However... it's really big. Sorry. This should probably be loaded in a separate chunk or something.
TODO: I just hack setting window.lz4 down below! This is not robust, but it works fine for now.
LICENSE: Xpra was Licensed under MPL 2.0. This was the license of the frontend client when I copied this code from Xpra. This code says:
* LZ4 based compression and decompression
* Copyright (c) 2014 Pierre Curto
* MIT Licensed