*: 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/lib/routemap.c b/lib/routemap.c
index 7302e23..c392226 100644
--- a/lib/routemap.c
+++ b/lib/routemap.c
@@ -1299,6 +1299,32 @@
   1
 };
 
+/* Common route map rules */
+
+void *
+route_map_rule_tag_compile (const char *arg)
+{
+  unsigned long int tmp;
+  char *endptr;
+  route_tag_t *tag;
+
+  errno = 0;
+  tmp = strtoul(arg, &endptr, 0);
+  if (arg[0] == '\0' || *endptr != '\0' || errno || tmp > ROUTE_TAG_MAX)
+    return NULL;
+
+  tag = XMALLOC(MTYPE_ROUTE_MAP_COMPILED, sizeof(*tag));
+  *tag = tmp;
+
+  return tag;
+}
+
+void
+route_map_rule_tag_free (void *rule)
+{
+  XFREE (MTYPE_ROUTE_MAP_COMPILED, rule);
+}
+
 /* Initialization of route map vector. */
 void
 route_map_init_vty (void)
diff --git a/lib/routemap.h b/lib/routemap.h
index 2479c81..48fafaf 100644
--- a/lib/routemap.h
+++ b/lib/routemap.h
@@ -196,4 +196,7 @@
 extern void route_map_delete_hook (void (*func) (const char *));
 extern void route_map_event_hook (void (*func) (route_map_event_t, const char *));
 
+extern void *route_map_rule_tag_compile (const char *arg);
+extern void route_map_rule_tag_free (void *rule);
+
 #endif /* _ZEBRA_ROUTEMAP_H */
diff --git a/lib/zclient.c b/lib/zclient.c
index eb8de1a..a32faaa 100644
--- a/lib/zclient.c
+++ b/lib/zclient.c
@@ -530,7 +530,7 @@
   * If ZAPI_MESSAGE_METRIC is set, the metric value is written as an 8
   * byte value.
   *
-  * If ZAPI_MESSAGE_TAG is set, the tag value is written as a 2 byte value
+  * If ZAPI_MESSAGE_TAG is set, the tag value is written as a 4 byte value
   *
   * XXX: No attention paid to alignment.
   */