#275: helper.php, add 'Obj_Data' class definition
#275: load_logic.php, remove 'Obj_Data' class definition
Merge pull request #276 from jeff1evesque/php_helper

#275: Move 'class Obj_Data' to 'php/helper.php'
Merge branch 'master' into php_load_dataset
#272: load_dataset.php, comment out 'var_dump()'