CLDSRV-873: return checksum in HeadObject and GetObject#6117

leif-scality wants to merge 15 commits intoimprovement/CLDSRV-872-store-checksum-in-object-metadatascality/cloudserver:improvement/CLDSRV-872-store-checksum-in-object-metadatafrom

improvement/CLDSRV-873-head-get-object-return-checksumscality/cloudserver:improvement/CLDSRV-873-head-get-object-return-checksumCopy head branch name to clipboard