Add bar/marker to timeline indicating the current time.

* Implementation of now marker does not add models to any scope
  because the time update is a consistently recurring operation.
  Adding a model to the scope would needlessly increase digest loop
  computations.

* The initial setting of the current time and the call to
  "setInterval" are put in the "viewCtrl" initialization block because
  obtaining the offset for marker position requires "$rootScope.wake"
  (and sleep) to be present.