[development] Cleaner and more consistent code.

[ojacquet at jax.be]

After reading Larry's blog post and some of the links referred there it
seems there's a strong movement for using PDO in D7 which would render the
whole point moot. So the only question left is to see if there's support
for refactoring the core of drupal 6 to one of the two functions. And if
there is, which? Is there even time to do this?