bookmarks: backed out new message from changeset 52c7e171e355 Not strictly a bugfix, hasn't achieved consensus yet.

clone: print bookmark name when clone activates a bookmark Similar to the message that prints the checked out branch name. Without this, the user might accidentally move the @ bookmark.

clone: activate @ bookmark if updating to it The message "updating bookmark @ failed!" in test-bookmarks-pushpull.t is correct, because the changeset that the @ bookmark points to is not pushed to the target repository.