Create parent for parser classes CRM-11254

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* CRM-11254: Create parent class for import
  http://issues.civicrm.org/jira/browse/CRM-11254
Update calls to class constants CRM-11254

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* CRM-11254: Create parent class for import
  http://issues.civicrm.org/jira/browse/CRM-11254
Move redundant parser code into parent CRM-11254

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* CRM-11254: Create parent class for import
  http://issues.civicrm.org/jira/browse/CRM-11254
Create parent for Import/Form/Summary CRM-11254

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* CRM-11254: Create parent class for import
  http://issues.civicrm.org/jira/browse/CRM-11254
Merge stateMachine into one file CRM-11254

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* CRM-11254: Create parent class for import
  http://issues.civicrm.org/jira/browse/CRM-11254
Standardize on name DataSource instead of UploadFile CRM-11254

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* CRM-11254: Create parent class for import
  http://issues.civicrm.org/jira/browse/CRM-11254
Create parent for Import/Form/Preview CRM-11254

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* CRM-11254: Create parent class for import
  http://issues.civicrm.org/jira/browse/CRM-11254
Create parent for Import/Form/MapField CRM-11254

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* CRM-11254: Create parent class for import
  http://issues.civicrm.org/jira/browse/CRM-11254
Merge pull request #1014 from colemanw/importParser

Refactor import parser code to use parent classes