Refactor Led state.isOn fix to avoid getting stuck in an infinite interval. Closes gh-341

Signed-off-by: Rick Waldron <waldron.rick@gmail.com>
v0.7.35

Signed-off-by: Rick Waldron <waldron.rick@gmail.com>
Servo.Continuous alias class

Signed-off-by: Rick Waldron <waldron.rick@gmail.com>
v0.7.36

Signed-off-by: Rick Waldron <waldron.rick@gmail.com>
Moved the status into stop