notice fixes
fixes for CRM-13587, due to mysql limitations drop and rebuild trigger

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* CRM-13587: Can't update table 'civicrm_contact' in stored function/trigger because it is already used by statement which invoked this stored function/trigger
  http://issues.civicrm.org/jira/browse/CRM-13587
Merge pull request #1973 from kurund/CRM-13587

CRM-13587, fixes trigger issue while updating custom group - contact subtypes