bug: historical importer does not create ItemDeviceType

[bwdmonkey]

Requirements

• For some Items in the system, there are data with no ItemDeviceType connections. We need to figure out why and resolve this issue.
• We could be losing data

[bwdmonkey]

$ make shell
>>> from app.models import Item, ItemDevice
>>> Item.objects.filter(device__in=ItemDevice.objects.filter(dtype_id=None)).count()
18163