Don't require a bootstrapped Drupal site for "drush drupal-org-login".

Also:
* Casts $drupal_password to a string before passing it on. I used this locally
  to implement a class with a __toString() method that does a drush_prompt() to
  ask the user for the password only when it is actually needed. That way the
  password does not need to saved in the settings.php file.
* Fixes a bunch of code-style issues.