Add OSGWidget::wid to get access to the window ID from Python.

include/gepetto/gui/osgwidget.hh

@@ -39,6 +39,8 @@ namespace gepetto {
         /// Replace the camera at her home position.
         virtual void onHome();
 
+        int wid () const;
+
         void addFloor();
         void attachToWindow (const std::string nodeName);
 

src/gui/osgwidget.cc

@@ -165,6 +165,11 @@ namespace gepetto {
       return wid_;
     }
 
+    int OSGWidget::wid() const
+    {
+      return int(wid_);
+    }
+
     graphics::WindowManagerPtr_t OSGWidget::window() const
     {
       return wm_;