1. many (minor) listbox fixes

2. scrollbar thumb now has min size


git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/branches/wxUNIVERSAL@8591 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775

src/univ/scrolbar.cpp

@@ -271,7 +271,6 @@ void wxScrollBar::OnIdle(wxIdleEvent& event)
 #endif // 0/1
                     }
 
-                    // FIXME: rect is client or win (must be client)?
                     Refresh(TRUE, &rect);
                 }