CRM-13263, CRM-13264

Cleaned up so that all field properties including title are inherited from DAO::export() keeping names/ titles consistent and standardized.
Simplified _columns array and improved CRM/Report/Form.php so parent class adds most of the default fillers for _column['filters'].
Removed / cleaned-up non-group-by fields from job and custom set fields.
Fixed all test cases per the changes made.