*: 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/pimd/pim_zebra.c b/pimd/pim_zebra.c
index 7072a3b..efff100 100644
--- a/pimd/pim_zebra.c
+++ b/pimd/pim_zebra.c
@@ -582,6 +582,11 @@
     stream_getl(s) :
     0;
 
+  if (CHECK_FLAG (api.message, ZAPI_MESSAGE_TAG))
+    api.tag = stream_getl (s);
+  else
+    api.tag = 0;
+
   switch (command) {
   case ZEBRA_IPV4_ROUTE_ADD:
     if (PIM_DEBUG_ZEBRA) {