iphlpapi: Intel Mac do not implement /proc filesystem so return Unimplemented for the functions trying to read from there.

[Juan Lang]

Hi Aric,

@@ -104,6 +104,9 @@ DWORD getInterfaceStatsByName(const char
 {
   FILE *fp;

+#ifdef __APPLE__
+  return ERROR_NOT_SUPPORTED;
+#endif

This is ugly.  Why not just change the case when fp is NULL?  You've
already got:
  fp = fopen("/proc/net/dev", "r");
  if (fp) {
...
  }
  else
     ERR ("unimplemented!\n");

You could change this to set the return value, rather than using all
these #ifdefs.  Same thing throughout the patch.
--Juan