BUGFIX: The 'attribute' argument of EmbeddedListField was ignored.

The 'attribute' argument of EmbeddedListField was ignored.

For example, in the following situation:

class UserResource(resources.MongoEngineResource):

    children = fields.EmbeddedListField(
        of=WishResource,
        attribute='childList',
        full=True,
        null=True
    )

This will try to acces the 'children' attribute instead of 'childList'.