(mu_header_append,mu_header_prepend): New function

@@ -85,6 +85,10 @@ extern int mu_header_clear_modified (mu_header_t);
 /* Set and get field values by field name. */
 extern int mu_header_set_value (mu_header_t, const char *, const char *, int);
 extern int mu_header_remove (mu_header_t, const char *, int);
+extern int mu_header_append (mu_header_t header, const char *fn,
+			     const char *fv);
+extern int mu_header_prepend (mu_header_t header, const char *fn,
+			      const char *fv);
 extern int mu_header_insert (mu_header_t, const char *, const char *, 
 			     const char *, int, int);
   

@@ -584,6 +584,48 @@ mu_header_remove (mu_header_t header, const char *fn, int n)
 }
 
 int
+mu_header_append (mu_header_t header, const char *fn, const char *fv)
+{
+  int status;
+  struct mu_hdrent *ent;
+
+  if (header == NULL || fn == NULL || fv == NULL)
+    return EINVAL;
+
+  status = mu_header_fill (header);
+  if (status)
+    return status;
+
+  ent = mu_hdrent_create (header, NULL, fn, strlen (fn), fv, strlen (fv));
+  if (!ent)
+    return ENOMEM;
+  mu_hdrent_append (header, ent);
+  HEADER_SET_MODIFIED (header);
+  return 0;
+}
+
+int
+mu_header_prepend (mu_header_t header, const char *fn, const char *fv)
+{
+  int status;
+  struct mu_hdrent *ent;
+
+  if (header == NULL || fn == NULL || fv == NULL)
+    return EINVAL;
+
+  status = mu_header_fill (header);
+  if (status)
+    return status;
+
+  ent = mu_hdrent_create (header, NULL, fn, strlen (fn), fv, strlen (fv));
+  if (!ent)
+    return ENOMEM;
+  mu_hdrent_prepend (header, ent);
+  HEADER_SET_MODIFIED (header);
+  return 0;
+}
+
+int
 mu_header_insert (mu_header_t header,
 		  const char *fn, const char *fv, 
 		  const char *ref, int n, int flags)
@@ -1189,3 +1231,4 @@ mu_header_clear_modified (mu_header_t header)
   return 0;
 }
 
+