One-to-one writable, nested serializer support
one 2 one nested relationships
Clean out ModelSerializer special casing from Serializer.field_from_native
Merge branch 'basic-nested-serialization' into one-to-one-nested-wip
Remove erronous _delete attribute
Remove unneeded arguments to save_object
Clean up and comment `restore_object`
Fixes to save_object
Fixes to save_object
Merge pull request #735 from tomchristie/one-to-one-nested-wip

One to one writable nested model serializers (wip)