Fix preprocessor issues and delete python widget first.

include/gepetto/gui/config-dep.hh.in

 #ifndef GEPETTO_GUI_CONFIG_DEP_HH
-# define PYTHON_CONFIG_DEP_HH
+# define GEPETTO_GUI_CONFIG_DEP_HH
 
 #cmakedefine01 GEPETTO_GUI_HAS_PYTHONQT
 
-#endif // PYTHON_CONFIG_PYTHON_DEP_HH
+#endif // GEPETTO_GUI_CONFIG_DEP_HH

src/gui/mainwindow.cc

@@ -67,6 +67,10 @@ namespace gepetto {
 
     MainWindow::~MainWindow()
     {
+#if GEPETTO_GUI_HAS_PYTHONQT
+      removeDockWidget(pythonWidget_);
+      delete pythonWidget_;
+#endif
       osgViewerManagers_.reset();
       worker_.quit();
       if (osgServer_ != NULL) {
@@ -197,7 +201,7 @@ namespace gepetto {
         centralWidget_ = osgWidget;
         centralWidget_->setObjectName(objName);
         setCentralWidget(centralWidget_);
-	#if PYTHONQT_NEED_INCLUDE==1
+	#if GEPETTO_GUI_HAS_PYTHONQT
         pythonWidget_->addToContext("osg", centralWidget_);
 	#endif
         connect(ui_->actionHome, SIGNAL (triggered()), centralWidget_, SLOT (onHome()));