Broken link in qtestlib tutorial 5

Cahpter 5 of the qtestlib tutorial contains a link to qtestlib-tools on the qt-labs site. This link no longer works. The same broken link also appears in the qt-labs article on graphing test results linked from the same tutorial.

It would be worth checking whether the stuff in the labs article still works, as some charting code was removed from qtestlib in Qt 4.7.