Log Message:
Update drupal6 package to 6.24.

Drupal 6.24, 2012-02-01
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- Improved performance of search indexing and user operations by adding indexes.
- Fixed issues with themes getting disabled due to missing locking in
  system_theme_data().
- Fix issue with blocks being disabled on updates in _block_rehash().
- Further improvements to PHP 5.3, PHP 4 and PostgreSQL compatibility.
- Improved code documentation at various places.
- Fixed a variety of other bugs.