title: How to occupy multiple columns or rows in GridLayout with QML?
body: <p>i want to know  how to occupy multiple columns or rows in GridLayout.follow is my code .</p>
  
  <pre><code>import QtQuick 2.4
  import QtQuick.Controls 1.3
  import QtQuick.Layouts 1.1
  
  Rectangle {
          width: 320
          height: 250
  
          GridLayout {
              anchors.left: parent.left
              anchors.bottom: parent.bottom
  
              rows: 2
              columns: 3
  
              Button{
                      text: "one"
                  }
  
              Button{
                      text: "two"
                  }
  
              Button{
                      text: "three"
                  }
  
              Button{
                      text: "four"
                  }
  
              Button{
                      text: "five"
                  }
                  Layout.columnSpan: 2
  
              }
      }
  </code></pre>
  
  <p>i want to how to make the "five" button occupy two columns. thank you !</p>