title: Q_OBJECT macro in custom class causes issues
body: <p>I am trying to create a custom widgetclass which inherits from QWidget.
  The problem is, that as I add the Q_OBJECT macro to my custom class, the widget doesn't get displayed (no erros). If I remove the macro run qmake und run the project again, the customwidget is shown. I am used to add the Q_Object macro because I want to add signals and slots.</p>
  
  <p>Widget.h:</p>
  
  <pre><code>#ifndef WIDGET_H
  #define WIDGET_H
  
  #include &lt;QWidget&gt;
  
  
  class Widget : public QWidget
  {
      Q_OBJECT
  
      public:
          Widget(QWidget *parent = 0);
  
  };
  
  #endif // WIDGET_H
  </code></pre>
  
  <p>Widget.cpp:</p>
  
  <pre><code>#include "Widget.h"
  
  Widget::Widget(QWidget *parent) : QWidget(parent) { }
  </code></pre>
  
  <p>main.cpp:</p>
  
  <pre><code>#include "Widget.h"
  
  #include &lt;QApplication&gt;
  #include &lt;QWidget&gt;
  #include &lt;QPoint&gt;
  
  
  int main(int argc, char *argv[])
  {
      QApplication a(argc, argv);
  
      QWidget window_main;
  
  
      Widget *widget_steps = new Widget(&amp;window_main);
      widget_steps-&gt;setFixedWidth(100);
      widget_steps-&gt;setFixedHeight(100);
      widget_steps-&gt;move(QPoint(0, 0));
      widget_steps-&gt;setStyleSheet("background-color: red");
  
  
      window_main.showMaximized();
  
      return a.exec();
  }
  </code></pre>
  
  <p>Without Q_OBJECT macro a red rect is shown on the upper-left corner, if I add the macro, it isn't shown. I am using Qt 5.1 and Windows 7.</p>
  
  <p>I am new to Qt, so please keep your answers simple  :)</p>