RemoveReferenceFromCollection not implemented! And better support for the 'propertyName' argument!

[legacy-carlostorrao]

Hi again. I notice that following limitations / issues in the current version of the Toolkit:

(1) AddReferenceToCollection do not store anywhere the 'propertyName' argument, and for my use-case this argument is mandatory, or else, I cannot know exactly in which sub-property exactly of an entity should be added the new entity. E.g. POST http://server/OData.svc/Users('foo')/$links/Products
If the Users entity have the same Type for /Products and for /SpecialProducts is impossible to know where to add the new entity in which collection.
My change was the following:

public void AddReferenceToCollection(object targetResource, string propertyName, object resourceToBeAdded)
{
this._currentOperation = "AddReferenceToCollection";
this._currentOperationProperty = propertyName;
this._currentEntity = targetResource;
this._currentRelatedEntity = resourceToBeAdded;
}

    [...]

    public void SaveChanges()
    {
        if (_currentOperation == null)
            return;

        var repository = RepositoryFor(_currentEntity.GetType().FullName);

        if (repository == null)
            return;

        if (_currentOperation == "CreateResource" || _currentOperation == "ModifyResource")
            ExecuteMethodIfExists(repository, "Save", _currentEntity);

        if (_currentOperation == "DeleteResource")
            ExecuteMethodIfExists(repository, "Remove", _currentEntity);

        if (_currentOperation == "AddReferenceToCollection")
            ExecuteMethodIfExists(repository, string.Format("Create{0}Relation", _currentOperationProperty), _currentEntity, _currentRelatedEntity);

        if (_currentOperation == "RemoveReferenceFromCollection")
            ExecuteMethodIfExists(repository, string.Format("Remove{0}Relation", _currentOperationProperty), _currentEntity, _currentRelatedEntity);
    }

(2) RemoveReferenceFromCollection is not implemented. This do not work for the following example:

DELETE http://server/OData.svc/Users('foo')/$links/Products('xpto')

I adapted the Add implementation to this Remove method, and this was the result:

public void RemoveReferenceFromCollection(object targetResource, string propertyName, object resourceToBeRemoved)
{
this._currentOperation = "RemoveReferenceFromCollection";
this._currentOperationProperty = propertyName;
this._currentEntity = targetResource;
this._currentRelatedEntity = resourceToBeRemoved;
}