Create a SensorWatch model and daemon
TrackSensor uses common format for single & multi lane modes

...and some documentation and better variable naming.
RaceManager tracks the current Heat and records Run times
Get rid of unnecessary scaffold css

It was messing up stuff on other pages.
Only update SensorState when it changes; check every tick
Merge RaceManager into SensorWatch; RaceManager validates heats

This greatly simplifies communication between classes.
Observers will be used to watch for database updates triggered by SensorWatch.
Create Derby model
Add migrations for existing models
Websocket notifications via Faye
Dashboard provides json for the dashboard
Practice races
Clear out Run records when Contestants and Heats are destroyed
Move logging to ApplicationHelper, and log some
Show Dashboard json on /board; reduce delay to 1s
Use a relative path for the Rails gem
Use foreman to start services
use Rack::ContentLength so Thin will run

https://github.com/faye/faye/issues/190
SensorWatch writes its own pid for foreground mode
Always trigger race starts while there is an active race

This will help when the device gets reset or is in an unexpected state.
Dashboard json includes the device status