Doc: "Getting Started" tutorial is outdated

In Qt Creator 3.0, the list of project templates has changed quite significantly. This tutorial should be updated: http://qt-project.org/doc/qt-5.1/qtdoc/gettingstartedqt.html

• The 2nd screenshot should be updated (see attachment)
• References to "Qt Gui Application" should be replaced with "Qt Widgets Application" – "Qt Gui Application" no longer exists, and this broken reference is a likely stumbling block for newcomers

To preserve the look-and-feel across the tutorial, the new screenshot should be taken on a Mac.