This PR also does backend format change to 1.0.1 from 1.0.0. Backward compatible changes are still kept to read the 'md5Sum' key. But all new objects will be stored with the same details under 'etag'. Fixes #4312
Fixes #2015
- xl-v1-bucket.go - removes a whole bunch of code. - {xl-v1,fs-v1}-metadata.go - add a lot of comments and rename functions appropriately.