Extract strlcpy and strlcmp to libtor-string

src/lib/string/compat_string.c

@@ -0,0 +1,14 @@
+/* Copyright (c) 2003-2004, Roger Dingledine
+ * Copyright (c) 2004-2006, Roger Dingledine, Nick Mathewson.
+ * Copyright (c) 2007-2018, The Tor Project, Inc. */
+/* See LICENSE for licensing information */
+
+#include "lib/string/compat_string.h"
+
+/* Inline the strl functions if the platform doesn't have them. */
+#ifndef HAVE_STRLCPY
+#include "strlcpy.c"
+#endif
+#ifndef HAVE_STRLCAT
+#include "strlcat.c"
+#endif