This command works similarly to "git config" - it parses repo and
cache configs to get, set, and delete values. It only works on local
repos so a malicious client can't e.g. override their storage quota
or reset the append_only flag.
Add tests for borg config
Add documentation for borg config
Change manual config edits -> borg config
There were a couple places in the documentation where it was advised
to edit the repository or cache config file, a process that is stream-
lined by borg config.
