improve determining complex object / complex-object item

[briesenberg07]

See select_data_for_checks() > elif which == 'complex' / elif which == 'item'

[briesenberg07]

See od2 metadata discussion 7-15 > see decision

[briesenberg07]

What was metadeities decision?
Seems like resource_type = dcmitype:Collection + model = generic should be the logic??