Duplicate model registration

[alexjreich]

Not sure if this goes in storage or admin:

Using both HasModels and Admin classes on the same module results in model being registered twice. This causes waterline to always throw an id validation error on save.

[loppear]

Ok, so the theory here is that HasModels (and therefore EditController, AdminController, etc) will look for a ./models directory, and projects have worked up til now for mostly having these controllers in a ./admin or ./controllers sibling dir rather than in the module root.

Fix is probably in nxus-storage to not duplicate registration of the same model file/id, last one wins.