facts caching: fix missing json in jsonfile caching
Use "override" instead of "loaded second" to be clear about what happens

Need for clarification brought up here:
https://github.com/ansible/ansible/issues/9877
Merge pull request #9881 from resmo/fix/missing-json-jsonfile-caching

facts caching: fix missing json in jsonfile caching
Restore json import for redis as well.  Switch preference to simplejson for speed
Pull in apt changes