Can ember data handle failing more gracefully when underlying data is deleted?

[tangollama]

My system has a patient document that is completely deleted. That delete didn't cascade to things like the imaging request queue. As a result, my imaging index route isn't rendering.

Expected behavior:
Imaging index route renders, regardless of data issues.

Actual behavior:
Error.

Console is producing the following error message.

Error while processing route: imaging.index Assertion Failed: You looked up the 'patient' relationship on a 'imaging' with id 6C16C18A-1FCE-35A0-9777-47DD2F55C957 but some of the associated records were not loaded. Either make sure they are all loaded together with the parent record, or specify that the relationship is async (DS.belongsTo({ async: true })) Error: Assertion Failed: You looked up the 'patient' relationship on a 'imaging' with id 6C16C18A-1FCE-35A0-9777-47DD2F55C957 but some of the associated records were not loaded. Either make sure they are all loaded together with the parent record, or specify that the relationship is async (DS.belongsTo({ async: true }))

Steps to reproduce:
Enter a patient, enter a visit and imaging request. Don't fulfill it. Delete the patient. Go back to the imaging index route. Error!!

[jkleinsc]

I am closing this issue because #380 and #381 makes sure that this issue doesn't happen any more.