Add `MINIO_API_EXTEND_LIST_CACHE_LIFE` that will extend
the life of generated caches for a while.
This changes caches to remain valid until no updates have been
received for the specified time plus a fixed margin.
This also changes the caches from being invalidated when the *first*
set finishes until the *last* set has finished plus the specified time
has passed.
configurable remote transport timeouts for some special cases
where this value needs to be bumped to a higher value when
transferring large data between federated instances.
This PR adds a new configuration parameter which allows readiness
check to respond within 10secs, this can be reduced to a lower value
if necessary using
```
mc admin config set api ready_deadline=5s
```
or
```
export MINIO_API_READY_DEADLINE=5s
```
Add two new configuration entries, api.requests-max and
api.requests-deadline which have the same role of
MINIO_API_REQUESTS_MAX and MINIO_API_REQUESTS_DEADLINE.
Klaus Post