The progress is tracked from the org.apache.myfaces.trinidad.model.BoundedRangeModel
attached to this component through its 'value' attribute. The progressIndicator element goes to an indeterminate
mode and shows up as a spinner animation if the 'value' or 'maximum' from the BoundedRangeModel is unknown.
When these gets known the component switches to a determinate mode and renders a progress bar indicating
percentage of task completion. Once the task is complete, ActionEvent is queued and, the page indicated by
outcome of 'action' attribute is navigated to.