Introduced new GUIEventAdatper singleton for sharing the current state between

multiple GraphicsWindows, this singleton is accessable via GUIEventEvent::getAccumulatedEventState().

Added use of this new singleton in GraphicsWindow* implementations.

Added WindowSizeHandler to osgkeyboard to help with debugging of event state
between windows.

src/osgGA/GUIEventAdapter.cpp

@@ -15,6 +15,13 @@
 
 using namespace osgGA;
 
+
+osg::ref_ptr<GUIEventAdapter>& GUIEventAdapter::getAccumulatedEventState()
+{
+    static osg::ref_ptr<GUIEventAdapter> s_eventState = new GUIEventAdapter;
+    return s_eventState;
+}
+
 GUIEventAdapter::GUIEventAdapter():
     _handled(false),
     _eventType(NONE),

src/osgViewer/GraphicsWindowCarbon.cpp

@@ -485,6 +485,10 @@ struct OSXCarbonWindowingSystemInterface : public osg::GraphicsContext::Windowin
 
 void GraphicsWindowCarbon::init()
 {
+    if (_initialized) return;
+
+    getEventQueue()->setCurrentEventState(osgGA::GUIEventAdapter::getAccumulatedEventState().get());
+
     _windowTitleHeight = 0;
     _closeRequested = false;
     _ownsWindow = false;

src/osgViewer/GraphicsWindowWin32.cpp

@@ -1010,6 +1010,8 @@ void GraphicsWindowWin32::init()
 {
     if (_initialized) return;
 
+    getEventQueue()->setCurrentEventState(osgGA::GUIEventAdapter::getAccumulatedEventState().get());
+
     WindowData *windowData = _traits.get() ? dynamic_cast<WindowData*>(_traits->inheritedWindowData.get()) : 0;
     HWND windowHandle = windowData ? windowData->_hwnd : 0;
 

src/osgViewer/GraphicsWindowX11.cpp

@@ -456,6 +456,8 @@ void GraphicsWindowX11::init()
         return;
     }
     
+    getEventQueue()->setCurrentEventState(osgGA::GUIEventAdapter::getAccumulatedEventState().get());
+    
     WindowData* inheritedWindowData =  dynamic_cast<WindowData*>(_traits->inheritedWindowData.get());
 
     _display = XOpenDisplay(_traits->displayName().c_str());