Working on relationship import options:
Remove unused exception method
Use KVC instead of building selector from name for importing relationships
Using KVC in data importer. Setting values to nil is a less common use case and can be handled in finalization callback when necessary
Add utilities for getting setter/getter selectors from properties
Use NSInvocation to set properties to nil if nil value in data
Replace interface with cascading methods, support for easy mapping overrides or more complex mapping definition
Refactor interface even further - relationship import done using mapping or property name
Add test for overriding related object mapping. Tedious but probably a less common use case