title: QML Loader memory leak?
body: <p>My application starts to consume large amount of memmory. First shot was MNG animation cache, but it seams that they are just not shared.
  So I created a TestItem with debug print in constructor/destructor, and I saw that Loader not working property when its source is changed via Video stop signal:</p>
  
  <pre class="lang-js prettyprint-override"><code>import QtQuick 1.1
  import QtMultimediaKit 1.1
  
  Rectangle {
      id:root
      width: 800
      height: 480
  
      Video {
          id: video1
          anchors.fill: parent
          source: "test.mp4" 
          onStopped: {
              loader1.source= "Test2.qml";
          }
      }
      Loader {
          id:loader1
          onSourceChanged: {
              console.debug("source changed to "+source)
          }
      }
      MouseArea {
          anchors.fill: parent
          onPressed: {
              loader1.source= "Test1.qml";
              video1.play();
          }
      }
  }
  </code></pre>
  
  <p>So when I click 4 times I get console output like this:</p>
  
  <pre><code>TestItem(0x1b4fc00) 
  source changed to file:///opt/Test/qml/TestLoaderBug/Test1.qml
  TestItem(0x2047ba0) 
  source changed to file:///opt/Test/qml/TestLoaderBug/Test2.qml
  TestItem(0x2046720) 
  source changed to file:///opt/Test/qml/TestLoaderBug/Test1.qml
  ~ TestItem(0x2047ba0) 
  TestItem(0x2050560) 
  source changed to file:///opt/Test/qml/TestLoaderBug/Test2.qml
  TestItem(0x204fad0) 
  source changed to file:///opt/Test/qml/TestLoaderBug/Test1.qml
  ~ TestItem(0x2050560) 
  TestItem(0x2051e40) 
  source changed to file:///opt/Test/qml/TestLoaderBug/Test2.qml
  TestItem(0x2051330) 
  source changed to file:///opt/Test/qml/TestLoaderBug/Test1.qml
  ~ TestItem(0x2051e40) 
  TestItem(0x2052e90) 
  source changed to file:///opt/Test/qml/TestLoaderBug/Test2.qml
  </code></pre>
  
  <p>And when I close my application, all remaing object are deleted:</p>
  
  <pre><code>~ TestItem(0x1b4fc00) 
  ~ TestItem(0x2046720) 
  ~ TestItem(0x204fad0) 
  ~ TestItem(0x2051330) 
  ~ TestItem(0x2052e90) 
  </code></pre>
  
  <p>Why the onStopped signal may produce such behavior?
  Is there any fix for this?</p>
  
  <p>Tested on Ubuntu 12.04 with libqt4-declarative(Version: 4:4.8.1-0ubuntu4.2) and libdeclarative-multimedia(Version: 1.2.0-1ubuntu2).</p>