- New command display-message (alias display) to display a message in the

status line (bound to "i" and displays the current window and time by
  default). The same substitutions are applied as for status-left/right.
- Add support for including the window index (#I), pane index (#P) and window
  name (#W) in the message, and status-left or status-right.
- Bump protocol version.

From Tiago Cunha, thanks!

cmd.c

@@ -41,6 +41,7 @@ const struct cmd_entry *cmd_table[] = {
 	&cmd_copy_mode_entry,
 	&cmd_delete_buffer_entry,
 	&cmd_detach_client_entry,
+	&cmd_display_message_entry,
 	&cmd_down_pane_entry,
 	&cmd_find_window_entry,
 	&cmd_has_session_entry,