Support bucket versioning (#9377)

- Implement a new xl.json 2.0.0 format to support,
  this moves the entire marshaling logic to POSIX
  layer, top layer always consumes a common FileInfo
  construct which simplifies the metadata reads.
- Implement list object versions
- Migrate to siphash from crchash for new deployments
  for object placements.

Fixes #2111

cmd/iam.go

@@ -469,7 +469,7 @@ func (sys *IAMSys) Init(ctx context.Context, objAPI ObjectLayer) {
 		}
 
 		// These messages only meant primarily for distributed setup, so only log during distributed setup.
-		if globalIsDistXL {
+		if globalIsDistErasure {
 			logger.Info("Waiting for all MinIO IAM sub-system to be initialized.. lock acquired")
 		}