seneca.alias method?

seneca.alias method?

https://github.com/senecajs/seneca-user/blob/bbc34b6801bc34328f14af60869616630d8c961d/user.js#L100

```javascript    .message('hook:password,cmd:pass', intern.make_msg('cmd_pass', ctx))

    // TODO seneca.alias method?
    .message('change:password', intern.make_msg('change_pass', ctx))

  return {
```