This commit adds simple variable expansion using either `$FOO`
or `${FOO}` when evaluating the config file. This can be disabled
by any command by using the `-no-expand-env` flag.
Previously, if a replica URL was specified then the `-config` flag
was silently ignored. This commit changes this behavior so that
specifying both the URL & config flag will now return an error.
This commits adds support for non-AWS S3-compatible storage such as
MinIO, Backblaze B2, & Google Cloud Storage (GCS). Other backends
should also work but some code has been added to make URL-based
configurations work more easily.
This commit refactors the commands to allow a replica URL when
restoring a database. If the first CLI arg is a URL with a scheme,
the it is treated as a replica URL.
