Added IFF handler.

Minor doc updates.
  Corrected configure for SGI OpenGL (wx-config related).


git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@13585 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775

include/wx/image.h

@@ -266,6 +266,7 @@ WXDLLEXPORT_DATA(extern wxImage)    wxNullImage;
 #include "wx/imagtiff.h"
 #include "wx/imagpnm.h"
 #include "wx/imagxpm.h"
+#include "wx/imagiff.h"
 
 #endif // wxUSE_IMAGE