Create new code paths for multiple subsystems in the code. This will
make maintaing this easier later.
Also introduce bugLogIf() for errors that should not happen in the first
place.
Make sure to pass a nil pointer as a Transport to minio-go when the API config
is not initialized, this will make sure that we do not pass an interface
with a known type but a nil value.
This will also fix the update of the API remote_transport_deadline
configuration without requiring the cluster restart.
Object names of directory objects qualified for ExpiredObjectAllVersions
must be encoded appropriately before calling on deletePrefix on their
erasure set.
e.g., a directory object and regular objects with overlapping prefixes
could lead to the expiration of regular objects, which is not the
intention of ILM.
```
bucket/dir/ ---> directory object
bucket/dir/obj-1
```
When `bucket/dir/` qualifies for expiration, the current implementation would
remove regular objects under the prefix `bucket/dir/`, in this case,
`bucket/dir/obj-1`.
