anchor.diff:        decision_board_style.opacity = '.4'
       else if selected_point
         decision_board_style.borderColor = "#ccc"
  -
   
       if your_opinion.published
         can_opine = permit 'update opinion', @proposal, your_opinion
  
positive.code:     2 * (m_x - h_x) / h_w - 1
  
    onMouseMove: (ev) -> 
      if @root.proposal_mode == 'results'
        hist = fetch('histogram')
        ev.stopPropagation()
  
negative.code:       save hist
  
    onMouseDown: (ev) -> 
      return if fetch('slider').is_moving
      ev.stopPropagation()
  
      hist = fetch('histogram')
  