XL/Multipart: Introduce "deleted" field for uploads.json (#1810)
XL/Multipart: Introduce "deleted" field for uploads.json (#1810)

To future proof backend in case #1805 becomes an issue.
donatello/minio,brendanashworth/minio,NitishT/minio,mf-00/newgo,alexellis/minio,dvstate/minio,mf-00/newgo,krishnasrinivas/minio,koolhead17/minio,harshavardhana/minio,aead/minio,rushenn/minio,balamurugana/minio,dvstate/minio,hackintoshrao/minio,krishnasrinivas/minio-daily,krishnasrinivas/minio-daily,jimjag/minio,krishnasrinivas/minio,dutchcoders/minio,aead/minio,rushenn/minio,krisis/minio,vadmeste/minio,mkash32/minio,jimjag/minio,harshavardhana/minio,dutchcoders/minio,fwessels/minio,rushenn/minio,hackintoshrao/minio,dvstate/minio,balamurugana/minio,donatello/minio,minio/minio,fwessels/minio,aead/minio,aead/minio,fwessels/minio,aead/minio,krishnasrinivas/minio,koolhead17/minio,brendanashworth/minio,luomeiqin/minio,fwessels/minio,harshavardhana/minio,alexellis/minio,jimjag/minio,hackintoshrao/minio,luomeiqin/minio,dutchcoders/minio,hackintoshrao/minio,abperiasamy/minio,harshavardhana/minio,abperiasamy/minio,NitishT/minio,harshavardhana/minio,vadmeste/minio,abperiasamy/minio,krishnasrinivas/minio,krisis/minio,rushenn/minio,luomeiqin/minio,aead/minio,brendanashworth/minio,NitishT/minio,jimjag/minio,NitishT/minio,dvstate/minio,brendanashworth/minio,dutchcoders/minio,luomeiqin/minio,harshavardhana/minio,harshavardhana/minio,mkash32/minio,minio/minio,abperiasamy/minio,aead/minio,aead/minio,harshavardhana/minio