Include wx/statbox.h according to precompiled headers of wx/wx.h (with other minor cleaning).

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@39487 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775

src/common/sizer.cpp

@@ -23,10 +23,10 @@
     #include "wx/math.h"
     #include "wx/utils.h"
     #include "wx/settings.h"
+    #include "wx/statbox.h"
 #endif // WX_PRECOMP
 
 #include "wx/sizer.h"
-#include "wx/statbox.h"
 #include "wx/listimpl.cpp"
 
 #if WXWIN_COMPATIBILITY_2_4