This will ensure each update item in the group resource config update history accurately lists all member resource config updates that were part of that group update item. Otherwise, some member updates could be missing and the user wouldn't even realize it.
this concerns the consistency of view for the group update. if we allow child deletions, the aggregate update in the history (see RHQ-1582) will look as if it was applied to a group with different membership.
i've uploaded a screenshot of what the resource history table looks like now after this fix
rev3156 - disallow resource-level updates from being deleted until the corresponding group update is deleted; provide a way to navigate from the resource update history page to the group history details page to make this group deletion easier;
This bug was previously known as http://jira.rhq-project.org/browse/RHQ-1583 Imported an attachment (id=368586)