More progress

- Script.SCRIPT_URL, Script.URL, and Script.BRANCH removed,
Script.DOWNLOAD_URL added.
- afterChannelJoin
- beforeNewMessage
- Cache.init (and cache initialisation)
- Cache#ensure changed (now accepts an object with key -> value)
- ChannelData#getData removed
- DataHash no longer stringifies DataHash.xxx as this is already done by
Cache
- Cache fields botSettings, motdSettings, autoMute, and
mostPlayersOnline added
- Different JSLint configuration
- Options.motd added
- Options.mostPlayersOnline added
- Options.AutoMute -> Options.autoMute
- Utils.scriptUpdateMessage
- Improved WatchUtils (Won't log when LogFile is falsy) and
WatchUtils.logSystemMessage