Fixed mime type detection .
Admin changes for static assets.
Added convenience method to RecordHelper to update or add an entity that will return both the actual entity and the admin "Entity" DTO.  Useful for custom persistence handlers that need to perform some operations on or with the entity before returning the Entity.
Changes for StaticAssets
View / Upload assets
Added EntityResult which is a tuple of Entity and the actual backing object.   Useful for CutomPersistenceHandlers that need to act with the source entity.
Assets