code: private boolean ready(Build.Task task) {
  		// FIXME: this is not a great solution in the long run for several reasons.
  		// Firstly, its possible that a given source will be rebuilt in the near future
  		// as a result of some other task and we should be waiting for that.
  		Path.Entry<?> target = task.getTarget();
  		for(Path.Entry<?> s : task.getSources()) {
  			if(s.lastModified() > target.lastModified()) {
  				return true;
  			}
  		}
  		return false;
  	}
docs: Check whether a given task is ready to be built. This is currently determined
  by having at least one source whose timestamp is in front of the target.
  
  @param task
  @return