Improve build and widget storage

There are no longer any qt headers included in wx/qt headers.
Applications do not need to link with qt librarys anymore, only wxqt libraries.
wxWindow and derived widgets only contain one pointer to their qtwidget, no longer
  carrying both base and derived pointers in parallel as was before.

include/wx/qt/evtloop.h

@@ -8,7 +8,7 @@
 #ifndef _WX_QT_EVTLOOP_H_
 #define _WX_QT_EVTLOOP_H_
 
-#include <QtCore/QTimer>
+class QTimer;
 
 class WXDLLIMPEXP_BASE wxQtEventLoopBase : public wxEventLoopBase
 {
@@ -58,21 +58,4 @@ public:
 
 #endif // wxUSE_GUI
 
-
-class wxQtEventLoopBase;
-
-class wxQtIdleTimer : public QTimer
-{
-
-public:
-    wxQtIdleTimer( wxQtEventLoopBase *eventLoop );
-    virtual bool eventFilter( QObject * watched, QEvent * event  );
-
-private:
-    void idle();
-
-private:
-    wxQtEventLoopBase *m_eventLoop;
-};
-
 #endif // _WX_QT_EVTLOOP_H_