use create_date and modified_date instead of civicrm_log table CRM-12753

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* CRM-12753: Searching for contacts by date created
  http://issues.civicrm.org/jira/browse/CRM-12753
use inner join and fixed label, CRM-12753

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* CRM-12753: Searching for contacts by date created
  http://issues.civicrm.org/jira/browse/CRM-12753
added js to change label, CRM-12753

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* CRM-12753: Searching for contacts by date created
  http://issues.civicrm.org/jira/browse/CRM-12753
CRM-12753, change labels according to selected options

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* CRM-12753: Searching for contacts by date created
  http://issues.civicrm.org/jira/browse/CRM-12753
Merge pull request #2263 from kurund/CRM-12753

CRM-12753, advanced search, change log fixes