[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.

from os.path import join
from cubicweb.toolsutils import create_dir

option_renamed('pyro-application-id', 'pyro-instance-id')

create_dir(join(config.appdatahome, 'backup'))