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

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@39505 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775

src/generic/grid.cpp

@@ -29,6 +29,7 @@
     #include "wx/valtext.h"
     #include "wx/intl.h"
     #include "wx/math.h"
+    #include "wx/listbox.h"
 #endif
 
 #include "wx/textfile.h"
@@ -4172,10 +4173,6 @@ wxGrid::~wxGrid()
 // be removed as well as the #else cases below.
 #define _USE_VISATTR 0
 
-#if _USE_VISATTR
-#include "wx/listbox.h"
-#endif
-
 void wxGrid::Create()
 {
     // set to true by CreateGrid