remove unnecessary GTK declarations from defs.h, move things only used once to the place that needs them

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@69020 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775

include/wx/gtk1/app.h

@@ -14,6 +14,8 @@
 #include "wx/icon.h"
 #include "wx/strconv.h"
 
+typedef struct _GdkVisual GdkVisual;
+
 //-----------------------------------------------------------------------------
 // classes
 //-----------------------------------------------------------------------------
@@ -53,7 +55,7 @@ public:
 
     bool IsInAssert() const { return m_isInAssert; }
 
-    gint            m_idleTag;
+    int             m_idleTag;
     void RemoveIdleTag();
 
     unsigned char  *m_colorCube;