* Addded a property description argument to -isValidObjectGraphContextForNewValue:

* Moved composite relationship validation into 
-isValidObjectGraphContextForNewValue:propertyDescription: 
(previously put in -validateTypeForNewValue:propertyDescription:)

* Reworked composite relationship validation to check both sides, and relaxed it 
to support a relationship between a transient parent and a persistent/transient child

Note: All EtoileUI tests pass again.


git-svn-id: svn://svn.gna.org/svn/etoile/trunk/Etoile/Frameworks/CoreObject@9801 7b3f36aa-e6db-49c1-8b4c-66eac1997e64