curl_memory: make curl_memory.h the second-last header file loaded

This header file must be included after all header files except
memdebug.h, as it does similar memory function redefinitions and can be
similarly affected by conflicting definitions in system or dependent
library headers.

lib/cookie.c

@@ -91,14 +91,14 @@ Example set of cookies:
 #include "strtok.h"
 #include "sendf.h"
 #include "slist.h"
-#include "curl_memory.h"
 #include "share.h"
 #include "strtoofft.h"
 #include "rawstr.h"
 #include "curl_memrchr.h"
 #include "inet_pton.h"
 
-/* The last #include file should be: */
+/* The last #include files should be: */
+#include "curl_memory.h"
 #include "memdebug.h"
 
 static void freecookie(struct Cookie *co)