API working again by assuming the UserGroup
Completed ATMO-375 and ATMO-384

* New Migrations remove ProviderSize (Deprecated)
* Add 'Size' key to InstanceStatusHistory
* Check for size on 'update_history'
* Call 'update_history' on every convert_esh_instance
* Lookup Size/Machine before converting if they are of type Mock*
Merge branch 'ATMO-375' into abyssinian-nightjar
Missing an import
Bad merge! All is well now
User is e-mailed upon submission of Imaging Request
missing import
Feature complete, added providertraits model, but not using it yet
Added 'Auto-Imaging' Trait and used it to determine whether to auto-image and auto-verify
Added migration for Adding and Assigning a new trait to a set of providers
Merge branch 'abyssinian-nightjar' of https://github.com/iPlantCollaborativeOpenSource/atmosphere