CRM-10189 - Drupal Rules Integration - Contact created/updated/deleted...

... event not firing

This fix was never applied to the Drupal6 stream so applying it now.

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* CRM-10189: Contact created/updated/deleted event not firing
  https://issues.civicrm.org/jira/browse/CRM-10189

QUESTION: (Seeing as this is my first git pull request. Woot.) I'd like to see this back ported to the 4.3, 4.4 and 4.5 branches also (as they seem to be still maintained, yes?) Is that something I would do and generate separate pull requests for each, effectively duplicating what I have done here for each branch or is that something your merge procedures do anyway? Happy to create the additional PR's.