Imports the converse forum software I wrote a few years ago. I want to
clean this up a bit and try using Hotwire with it.
Note: The original repository was AGPL-3.0 licensed. I'm the copyright
holder and have relicensed it to GPL-3.0 in the commit that is being
merged.
Imported from: https://github.com/tazjin/converse
git-subtree-dir: web/converse
git-subtree-mainline: 386afdc794
git-subtree-split: 09168021e7
Change-Id: Ia8b587db5174ef5b3c52910d3d027199150c58e0
