Set orientation for scrollbar events (backported from CVS head)

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/branches/WX_2_4_BRANCH@20006 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775

docs/changes.txt

@@ -200,6 +200,7 @@ wxGTK:
 wxMSW:
 
 - no longer take ampersand into account in wxStaticText::GetBestSize
+- set orientation for scrolbar events
 
 2.4.0
 -----

src/msw/scrolbar.cpp

@@ -239,6 +239,7 @@ bool wxScrollBar::MSWOnScroll(int WXUNUSED(orientation), WXWORD wParam,
     }
 
     wxScrollEvent event(scrollEvent, m_windowId);
+    event.SetOrientation(IsVertical() ? wxVERTICAL : wxHORIZONTAL);
     event.SetPosition(position);
     event.SetEventObject( this );