CRM-13282, fixed state default for membership billing block and code cleanup for offline event registration via CC

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* CRM-13282: Prefill billing address on back-office contribution via credit card and membership via credit card using profile.get api
  http://issues.civicrm.org/jira/browse/CRM-13282
Merge pull request #1520 from kurund/CRM-13282

CRM-13282, fixed state default for membership billing block and code cle...