Fix incorrect bounds being saved for MainWindow

Instead of saving the bounds of the UI component, save the bounds of the document window.

Author: anjaldoshi

Source/MainWindow.cpp

@@ -400,8 +400,8 @@ void MainWindow::saveWindowBounds()
     XmlElement* bounds = new XmlElement ("BOUNDS");
     bounds->setAttribute ("x", documentWindow->getScreenX());
     bounds->setAttribute ("y", documentWindow->getScreenY());
-    bounds->setAttribute ("w", documentWindow->getContentComponent()->getWidth());
-    bounds->setAttribute ("h", documentWindow->getContentComponent()->getHeight());
+    bounds->setAttribute ("w", documentWindow->getWidth());
+    bounds->setAttribute ("h", documentWindow->getHeight());
     bounds->setAttribute ("fullscreen", documentWindow->isFullScreen());
 
     xml->addChildElement (bounds);