persist: use cjson instead of json
persist: use cjson instead of json

Former-commit-id: d5c583273008a09ca8d6dd3deff9221a32a434f4 [formerly 2563aa0de95ca2e13b3bf0bfd87fa275eebb2275]
Former-commit-id: eac41729b85510c162b9f05fe905e16bae47ac28
torhve/ivar2,torhve/ivar2,haste/ivar2,torhve/ivar2