Fixes plus delete-functionality for the task editor.
- Do not display the attribute resource on load in the sample project.
- Fix a macos template-export issue.
- Initialize a previously-uninitialized ivar.
- Fix an incorrect return type in smtk::view::Selection.
- Fix a crash when unstructured data has no assigned IDs.
- Refactor deletion-via-operation-group.
- Add object deletion to the task-editor's "pan" mode.
Edited by David Thompson