Addresses review comment on s3api_bucket_handlers.go:880
Add comment documenting that ReadFilerConf uses the current active filer
from FilerClient (which is better than always using first filer), but
doesn't have built-in multi-filer failover.
Add TODO to update filer.ReadFilerConf to support multiple filers for
complete HA. For now, it uses the currently active/healthy filer tracked
by FilerClient which provides reasonable availability.
Chris Lu
1d7fded503