Don't use a weakref for compact_legislation cache, because it doesn't work at least for Paste web server.
Don't use a weakref for compact_legislation cache, because it doesn't work at least for Paste web server.

openfisca/openfisca-core,openfisca/openfisca-core,benjello/openfisca-core,sgmap/openfisca-core,adrienpacifico/openfisca-core,benjello/openfisca-core