This change adds a `Secret` property to `HelpKV` to identify secrets
like passwords and auth tokens that should not be revealed by the server
in its configuration fetching APIs. Configuration reporting APIs now do
not return secrets.
- New sub-system has "region" and "name" fields.
- `region` subsystem is marked as deprecated, however still works, unless the
new region parameter under `site` is set - in this case, the region subsystem is
ignored. `region` subsystem is hidden from top-level help (i.e. from `mc admin
config set myminio`), but appears when specifically requested (i.e. with `mc
admin config set myminio region`).
- MINIO_REGION, MINIO_REGION_NAME are supported as legacy environment variables for server region.
- Adds MINIO_SITE_REGION as the current environment variable to configure the
server region and MINIO_SITE_NAME for the site name.
This is to ensure that there are no projects
that try to import `minio/minio/pkg` into
their own repo. Any such common packages should
go to `https://github.com/minio/pkg`
