TODO.t2t: forget ether_ntoa() and Co.

ether_ntoa_r(), the reentrant version of ether_ntoa(), is a GNU
extension so using it would break portability. We will just stick with
our owl_mac_bytes_to_string() and owl_mac_bytes_to_string_r().

TODO.t2t

@@ -60,12 +60,6 @@ Work to do in OwlPS
   information. This will make easier to develop clients in other
   languages than C and over other protocols than UDP.
 
-- Use struct ether_addr to store MAC addresses
-
-  We could use the struct ether_addr to store binary MAC addresses, and
-  convert them to strings with ether_ntoa(3) instead of
-  owl_mac_bytes_to_string().
-
 - Add a library to parse aggregation files, handling the different
   formats ?