Externally visible changes since v1.2.0:
- Fall back to default IAM endpoint for S3 proxy.
- Refactor to allow concurrent inserts.
- Add option to mangle AC keys with (non-empty) instance names.
- Add new key format for S3 to avoid per-prefix rate limits.
- grpc bytestream: skip writes for preexisting blobs.
- Add prometheus disk cache size metrics.
- Add support for configuring uploaders and upload queue size.
- Support mTLS for authentication.
- Add the current number of goroutines to statistics.