joomla/joomla-platform — pull request #1136 by realityking (2012-04-08 19:43:11+00:00)
Title: Implement Countable in JDatabaseDriver + clean up

This allows us to use

```php
$db = JFactory::getDbo();
echo count($db);
```

instead of

```php
$db = JFactory::getDbo();
echo $db->getCount();
```

As for the clean up, it's mostly shifting deprecated code to JDatabase. It also moves JDatabaseException to legacy since we only keep it around for B/C purposes.