CRM-13737 allow drupal folder to be at the same level as the civicrm folder

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* CRM-13737: Restrucure drupal folder out of the civicrm folder
  http://issues.civicrm.org/jira/browse/CRM-13737

CRM-13737 tidy up previous commit

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* CRM-13737: Restrucure drupal folder out of the civicrm folder
  http://issues.civicrm.org/jira/browse/CRM-13737