CRM-12621 - Add skeletal org.civicrm.hremerg
CRM-12621 - hremerg - Fix default metadata
CRM-12621 - Generate skeletal upgraders
CRM-12621 - hrident, hrjob, hrmed, hrqual, hrvisa - Import custom data groups
CRM-12621 - hremerg - Create relationship type and associated custom data

The XML is loaded from a Smarty template because the importer does not know
how to target custom-data groups at specific relationship types.