Users of the Timer class may benefit from retrieving the timer deadline
after it times out. This is currently not possible as the deadline is
reset to 0 when the timer times out or is stopped. Fix this by not
resetting the deadline, and adding a new running_ field to the Timer
class to implement isRunning().
Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Reviewed-by: Niklas Söderlund <niklas.soderlund@ragnatech.se>
Reviewed-by: Jacopo Mondi <jacopo@jmondi.org>