Many changes in (mainly) kernel syncers.

- BSD kernel syncer is now self-conscious and can learn alien routes
- important bugfix in BSD kernel syncer (crash after protocol restart)
- many minor changes and bugfixes in kernel syncers and neighbor cache
- direct protocol does not generate host and link local routes
- min_scope check is removed, all routes have SCOPE_UNIVERSE by default
- also fixes some remaining compiler warnings

proto/bgp/packets.c

@@ -914,7 +914,6 @@ bgp_do_rx_update(struct bgp_conn *conn,
   rta *a = NULL;
   ip_addr prefix;
   net *n;
-  rte e;
   int err = 0, pxlen;
 
   p->mp_reach_len = 0;
@@ -936,8 +935,6 @@ bgp_do_rx_update(struct bgp_conn *conn,
 
   DO_NLRI(mp_reach)
     {
-      int i;
-
       /* Create fake NEXT_HOP attribute */
       if (len < 1 || (*x != 16 && *x != 32) || len < *x + 2)
 	goto bad;