[json] fix json serialization for recent simplejson implementation, and test encoding of entities as with earlier simplejson implementation, iterencode internal stuff is a generated function, we can't anymore rely on the _iterencode overriding trick, so move on by stoping isinstance(Entity, dict). This is a much heavier change than expected but it was expected to be done at some point, so let's go that way.

add_relation_type('prefered_form')

rql('SET X prefered_form Y WHERE Y canonical TRUE, X identical_to Y')
commit()

drop_attribute('EmailAddress', 'canonical')
drop_relation_definition('EmailAddress', 'identical_to', 'EmailAddress')

if 'see_also' in schema:
    sync_schema_props_perms('see_also', syncprops=False, syncrdefs=False)