Add XRC handler for wxSimplebook.

Similar to wxNotebook but even simpler as wxSimplebook doesn't use images.

Also add wxSimplebook::Create() as the version inherited from wxBookCtrlBase
didn't _quite_ work: we need to add wxBK_TOP style to prevent asserts due to
unknown alignment in the base class when creating wxSimplebook.

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@77010 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775

include/wx/simplebook.h

@@ -41,6 +41,16 @@ public:
         Init();
     }
 
+    bool Create(wxWindow *parent,
+                wxWindowID winid = wxID_ANY,
+                const wxPoint& pos = wxDefaultPosition,
+                const wxSize& size = wxDefaultSize,
+                long style = 0,
+                const wxString& name = wxEmptyString)
+    {
+        return wxBookCtrlBase::Create(parent, winid, pos, size, style | wxBK_TOP, name);
+    }
+
 
     // Methods specific to this class.