title: What deselect selected cell when navigationController pops a view?
body: <p>The default NavigationController template offered by apple, it has one navigationController and a table.</p>
  
  <p>And if you select a cell, a new view will be pushed into navigationController and if you pop the view, the selected cell will be de-hightlighted automatically. </p>
  
  <p>But how does table know when to de-hightlight it and how does it know which cell is selected??</p>
  
  <p>or does it just re-load all data again?</p>