As a sysadmin, I need to be able to reliably purge a concept/resource tree using Drush. The current script creates an array then purges from the parent downward to the
leaf objects. If it fails in the middle it leaves orphans. It needs to purge from the leaf objects upwards.

It must ensure that no child has more than one parent so it needs to keep the dry-run flag. And it should not depend solely on the triplestore because it could be inaccurate. We purge because things did not go well somewhere. It can use the triplestore to some extent but should walk the objects, and check the RELS-EXT to build the purge list from there (or provide information why it cannot proceed). Only resources and concepts are to be purged by this code.

Also, it only runs on an older version of drush, which is not really a problem, but it would be good to run on the recommended version of drush that matches workbench.

=====2016/05/13 Update=====
remove the ability to remove multiparent objects as option
do a check ahead of time, stop if find multiparent object
stop unless administrative user
give the ability remove an orphan (object that has no parent)