title: Inherited variable doesn't like new values
body: <p>Could someone explain me why:</p>
  
  <pre><code>abstract class Super(var title: String)
  
  class Sub(title: String) extends Super(title) {
      def test = println(title)
  }
  
  val s = new Sub("a")
  s.test
  s.title = "b"
  s.test
  </code></pre>
  
  <p>prints:</p>
  
  <pre><code>a
  a
  </code></pre>
  
  <p>instead of:</p>
  
  <pre><code>a
  b
  </code></pre>
  
  <p>?</p>