[#125] Handle negative Content-Length on put

Add computing actual object size during calculating hash on put.
Use this actual value to save in tree and cache

Signed-off-by: Denis Kirillov <d.kirillov@yadro.com>

api/layer/util.go

@@ -94,7 +94,7 @@ func objectInfoFromMeta(bkt *data.BucketInfo, meta *object.Object) *data.ObjectI
 		ContentType: mimeType,
 		Headers:     headers,
 		Owner:       *meta.OwnerID(),
-		Size:        int64(meta.PayloadSize()),
+		Size:        meta.PayloadSize(),
 		HashSum:     hex.EncodeToString(payloadChecksum.Value()),
 	}
 }