Disable test for setting the creation time under Unix.

Also document that this doesn't work there.

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@74424 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775

interface/wx/filename.h

@@ -1260,6 +1260,10 @@ public:
     /**
         Sets the file creation and last access/modification times (any of the pointers
         may be @NULL).
+
+        Notice that the file creation time can't be changed under Unix, so @a
+        dtCreate is ignored there (but @true is still returned). Under Windows
+        all three times can be set.
     */
     bool SetTimes(const wxDateTime* dtAccess,
                   const wxDateTime* dtMod,