Add a preservation_version config to sandbox filters exposing cbuf configs

- update http_status to include 100's (for Loop, but is good in general)
- add a unit test for http_status since it was modified and didn't have one
Duh. Sorry, I was getting my wires crossed btn what was coming from config and what was coming from persistence, and I was thinking we were going to be incrementing the persistent value every time, which would clearly not work. Thanks for clarifying.