CRM-13159 add missing period end of sentence and fix unrelated typo spelling in Address.php

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* CRM-13159: relationship.api to accept 'membership_type' as a param
  http://issues.civicrm.org/jira/browse/CRM-13159
Merge pull request #1411 from davecivicrm/CRM-13159

CRM-13159 add missing period end of sentence and fix unrelated typo spel...