Added the new pretty toString method

PitTree.scala

class PitTree[T](val children : Map[String, PitTree[T]], val value : Option[T]) extends Map[String, T] {
  def this() = this(Map(), None)
  def this(value : T) = this(Map(), Some(value))
  def update(path : String, upVal : T) : PitTree[T] = update(splitPath(path), upVal)
  def update(path : List[String], upVal : T) : PitTree[T] = path match {
    case Nil =>
      new PitTree[T](upVal)
    case h :: t =>
      val child = children.getOrElse(h, new PitTree[T]()).update(t, upVal)
      new PitTree[T](children + (h -> child), value)
  }
  def get(path : String) : Option[T] = get(splitPath(path))
  def get(path : List[String]) : Option[T] = path match {
    case Nil =>
      	value
    case h :: t =>
      	if(children.keysIterator.exists(_ == h))
      		children(h).get(t)
        else
        	None
  }
  
  def + [T1 >: T](kv: (String, T1)): PitTree[T] = this  // TODO: Implement me
  def - (key: String): PitTree[T] = this                // TODO: Implement me
  def iterator = Iterator()                             // TODO: Implement me

  def splitPath(path : String) = path.split('/').filter(_ != "").toList

  override def toString = ".\n"+toString(children.toList, "", "")
  
  def toString(children: List[(String, PitTree[T])], prefix: String, name: String): String = {
    def formatValue(o: Option[T]): String = o match {
      case Some(s) => "= " + s.toString
      case None => ""
    }
    children match {
      case Nil => ""
      case h::Nil => // last element
        val (name, subTree) = h
      	prefix + "`-- " + name + " " + formatValue(subTree.value) + "\n" + 
         toString(subTree.children.toList, prefix + "    ", name)
      case h::t =>
      	val (name, subTree) = h
      	prefix + "|-- " + name + " " + formatValue(subTree.value) + "\n" +
         toString(subTree.children.toList, prefix + "|   ", name) + 
         toString(t, prefix, name)
    }
  }
}

object PitTree {
  def apply[T]()                          = new PitTree[T]()
  def apply[T](value : T)                 = new PitTree[T](value)
}

object Test extends Application {  
	  var pitTree = PitTree[Int]()
	  pitTree = pitTree("/apa") = 10
	  pitTree = pitTree("/apa") = 20
	  pitTree = pitTree("gris/kossa/häst") = 30
	  pitTree = pitTree("gris/kossa/apa") = 10
	  pitTree = pitTree("gris/kossa/katt/firre") = 4
	  pitTree = pitTree("flodhaest") = 2
	  println(pitTree)
  //TODO: Add example with comments showing results of operations.
}