[WIP] 1.0 cleanup

TODO:

- [ ] auto-determine region when using `s3://` style URL
- [ ] specs for `box_add` extensions
- [ ] specs for error messages?
- functional tests
  - [ ] US standard simple (has non-standard endpoint)
  - [ ] non US standard simple
  - [ ] US standard simple 's3://' style
  - [ ] non US standard simple 's3://' style
  - [ ] S3 metadata
  - [ ] local metadata