Current master repeatedly calls ListBuckets() during
initialization of multiple sub-systems
Use single ListBuckets() call for each sub-system as
follows
- LifeCycle
- Policy
- Notification
It looks like from implementation point of view fastjson
parser pool doesn't behave the same way as expected
when dealing many `xl.json` from multiple disks.
The fastjson parser pool usage ends up returning incorrect
xl.json entries for checksums, with references pointing
to older entries. This led to the subtle bug where checksum
info is duplicated from a previous xl.json read of a different
file from different disk.
This PR is based off @sinhaashish's PR for object lifecycle
management, which includes support only for,
- Expiration of object
- Filter using object prefix (_not_ object tags)
N B the code for actual expiration of objects will be included in a
subsequent PR.
