Fix context help for examples

- createRightPaneContextViewer() needs to be called up-front. In the old
order, it would fail the first time.

- Queue opening of help, because we need the editor window to be drawn
  before it can be assessed wether to show the help in split mode

Change-Id: Ib2054285efb07ccbfaf3faf089085c16ba432be8
Reviewed-on: http://codereview.qt.nokia.com/22
Reviewed-by: Daniel Teske <daniel.teske@nokia.com>

src/plugins/help/helpplugin.cpp

@@ -838,9 +838,9 @@ HelpViewer* HelpPlugin::viewerForContextMode()
     }
 
     if (placeHolder && showSideBySide) {
+        createRightPaneContextViewer();
         RightPaneWidget::instance()->setWidget(m_rightPaneSideBarWidget);
         RightPaneWidget::instance()->setShown(true);
-        createRightPaneContextViewer();
         return m_helpViewerForSideBar;
     }