Upon losing connection, it will attempt to reconnect. If it successfully reconnects, the local client's canvas is cleared (in preparation to receive all new canvas data from the server), and the join dialog is brought back up. Hopefully later we can work on reconnecting as the same player.

Changed the "lost connection" message to be a little more friendly/descriptive.
Added a package.json that allows users to type "npm install" in the root drawthing/ directory and have npm automatically install dependencies.