v0.1.0

First release: a reaction-time game with per-channel leaderboards. In Concord the game runs in each player's client as sandboxed, signed code (publisher key fingerprint 3413 13a6 8077 8f8d 2b5e dd30 317f 4e7f). Needs a Concord client and server built from pre-v0.1.0-fixes at 8475bb2 or later.