adjust polling interval down to 50ms in js

This makes the UI feel more responsive when sending dirty data. In most cases,
the timeout routine does very little, so this shouldn't waste much CPU.
fix wrong dataSerial being incremented on sync

This was causing some autosync weirdness.
RTD: figure out when "goal" to go

If the yards to go are equal to the location of the ball, then the yards to go
should be displayed as "goal".
Implement penalty classes in sports

This allows a helper function to be created to create a penalty string
based on which sport is currently selected. Closes #11.
retab sports.json