CRM-12915, common js file for CiviHR to load revisions inside a tab

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* CRM-12915: Improve layout of revision-history for multi-row CustomGroups
  http://issues.civicrm.org/jira/browse/CRM-12915
Merge pull request #1263 from deepak-srivastava/revisions

CRM-12915, common js file for CiviHR to load revisions inside a tab