The new config loader requires some steps to happen in a different
order, particularly in regard to knowing the schema in order to
decode the configuration.
Here we lean directly on the configschema package, rather than
on helper/schema.Backend as before, because it's generally
sufficient for our needs here and this prepares us for the
helper/schema package later moving out into its own repository
to seed a "plugin SDK".
The `remote` backend config contains an attribute that is defined as a `*schema.Set`, but currently only `string` values are accepted as the `config` attribute is defined as a `schema.TypeMap`.
Additionally the `b.Validate()` method wasn’t called to prevent a possible panic in case of unexpected configurations being passed to `b.Configure()`.
This commit is a bit of a hack to be able to support this in the 0.11 series. The 0.12 series will have proper support, so when merging 0.12 this should be reverted again.
The "terraform" provider was previously split out into its own repository,
but that turned out to be a mistake due to how tightly it depends on
aspects of Terraform Core.
Here we prepare to bring it back into the core repository by reorganizing
the directory layout to conform with what's expected there.
Martin Atkins