Resource not found though listed but with less fields

[mdutoo]

Symptoms:

a Resource that can be seen in query results but with less fields that are stored (those invisible fields are still matching query criteria and follow sort choice) can't be gotten by single GET on its own URL.

Cause:

This Resource's type (first mixin) had been inheriting from another one that dictated a different storageModel (where it can still be found in queries), but this inheritance link has been removed since and therefore it's now looked up within the wrong storage model and inherited fields are not displayed anymore.

Solution: handle it in #25 manageable model with consistency checks and #62 data checks.