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

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@39106 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775

src/gtk/gnome/gprint.cpp

@@ -21,6 +21,7 @@
 
 #ifndef WX_PRECOMP
     #include "wx/log.h"
+    #include "wx/dcmemory.h"
 #endif
 
 #include "wx/math.h"
@@ -28,7 +29,6 @@
 #include "wx/gtk/private.h"
 #include "wx/module.h"
 #include "wx/dynlib.h"
-#include "wx/dcmemory.h"
 #include "wx/icon.h"
 
 #include <libgnomeprint/gnome-print.h>