*: Port Christians tweaks for 32-bit route tags

Port over Christian's tweaks from his port of my commit widening the
route-tag field width to 32-bit.  Commit dc9ffce8786844
 "*: Consistently support 32-bit route tags".

with "changes which make this actually useful for all the daemons".

This is missing the zebra route-map changes.
diff --git a/ripd/ripd.h b/ripd/ripd.h
index 5e87fcd..9dba1a5 100644
--- a/ripd/ripd.h
+++ b/ripd/ripd.h
@@ -223,7 +223,7 @@
   struct in_addr nexthop_out;
   u_char metric_set;
   u_int32_t metric_out;
-  u_short tag_out;
+  u_int16_t tag_out;
   ifindex_t ifindex_out;
 
   struct route_node *rp;