Added a few #if wxUSE_XXX

Regrouped image format handlers
  Updated the rest accordingly
  Added changes.txt for wxGTK


git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@2795 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775

include/wx/valtext.h

@@ -16,9 +16,9 @@
 #pragma interface "valtext.h"
 #endif
 
-#if defined(wxUSE_VALIDATORS) && !wxUSE_VALIDATORS
-    #error "wxWindows is compiled without support for wxValidator"
-#endif
+#include "wx/defs.h"
+
+#if wxUSE_VALIDATORS
 
 #include "wx/validate.h"
 
@@ -79,3 +79,7 @@ protected:
 };
 
 #endif
+  // wxUSE_VALIDATORS
+
+#endif
+  // _WX_VALTEXTH__