CRM-13621 - add ability to redirect to main entry point for public pages

----------------------------------------
* CRM-13621: Handle invalid session errors especially for public pages in a nicer manner
  http://issues.civicrm.org/jira/browse/CRM-13621
Merge branch '4.4' of github.com:civicrm/civicrm-core into CRM-13621
CRM-13621 - fix error messages

----------------------------------------
* CRM-13621: Handle invalid session errors especially for public pages in a nicer manner
  http://issues.civicrm.org/jira/browse/CRM-13621
CRM-13621 - fix error messages

----------------------------------------
* CRM-13621: Handle invalid session errors especially for public pages in a nicer manner
  http://issues.civicrm.org/jira/browse/CRM-13621
CRM-13575 - Elavon Payment Processor requires changes to conform to requirements

http://issues.civicrm.org/jira/browse/CRM-13575
Merge pull request #1840 from dlobo/CRM-13575

CRM-13575 - Elavon Payment Processor requires changes to conform to requirements
Merge pull request #1837 from dlobo/CRM-13621

CRM-13621