dangling objects when removed `mc admin heal -r` or crawler
auto heal would incorrectly return error - this can interfere
with usage calculation as the entry size for this would be
returned as `0`, instead upon success use the resultant
object size to calculate the final size for the object
and avoid reporting this in the log messages
Also do not set ObjectSize in healResultItem to be '-1'
this has an effect on crawler metrics calculating 1 byte
less for objects which seem to be missing their `xl.meta`
With reduced parity our write quorum should be same
as read quorum, but code was still assuming
```
readQuorum+1
```
In all situations which is not necessary.
- 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
