Revert "Merge pull request #3533 from rodrigosaito/include_id_in_only"

This breaks the following situation:
```
class MyModel
  default_scope -> { without(:some_field) }
end

MyModel.first
```

I will raise a Moped::Errors::QueryFailure, as a project cannot mix
inclusions and exclusions.

This reverts commit bde8ac1b0f16aaad7e343073ce8c5b5b9c9ffc5b, reversing
changes made to c8af8d0836b086cebc4a609037a97747e9f3359b.

Conflicts:
	lib/mongoid/attributes.rb