The Extra class is a prop used for extras (background characters).
If the pauseCel property is -1, the cel is set to a random number. If it is -2, the cel is set to the last cel. If the pauseCel is equal to the cycleType, the cel is set to the the pauseCel. Otherwise, the cel is set to the first cel.
Stops the Extra.
Sets the cel accordingly from pauseCel (see init), and they stops updating on it.
Sets the state property to 1.