This PR fixes all the below scenarios
and handles them correctly.
- existing data/bucket is replaced with
new content, no versioning enabled old
structure vanishes.
- existing data/bucket - enable versioning
before uploading any data, once versioning
enabled upload new content, old content
is preserved.
- suspend versioning on the bucket again, now
upload content again the old content is purged
since that is the default "null" version.
Additionally sync data after xl.json -> xl.meta
rename(), to avoid any surprises if there is a
crash during this rename operation.
- 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
