title: layout for qml custom tooltip
body: <p>I'm trying to create a custom tooltip in qml but am not able to force the widget to be displayed on top of other items in the layout. I know why qml behaves that way, but I can't find a method to make it behave like I want to.</p>
  
  <p>Here's the code that demonstrates the problem:</p>
  
  <pre><code>import QtQuick 2.3
  import QtQuick.Controls 1.2
  import QtQuick.Window 2.2
  
  ApplicationWindow {
      title: qsTr("Hello World")
      width: 640
      height: 480
  
  
      Flow {
          anchors.fill: parent
          anchors.margins: 10
          spacing: 5
  
          Repeater {
              model: ["foo", "bar", "buzz"]
  
              delegate: Item {
                  width: item.width
                  height: item.height
  
                  Rectangle {
                      id: item
                      color: "blue"
                      width: 100
                      height: 100
  
                      Text {
                          text: modelData
                          color: "white"
                          anchors.centerIn: parent
                      }
                  }
  
                  Rectangle {
                      width: 80
                      height: 120
                      color: "black"
                      anchors.left: item.right
                      anchors.leftMargin: 5
  
                      Text {
                          text: "tooltip"
                          color: "white"
                          anchors.centerIn: parent
                      }
                  }
              }
          }
      }
  }
  </code></pre>
  
  <p>What I want to have is the tooltips on top of other items in the list, not the other way around.</p>