These fixes are needed to make the provider work with master again.
These are still some issues, but they seem not to be related to the
provider, but the changes in `helper/schema`.
This is a refactored solution for PR #616. Functionally this is still
the same change, but it’s implemented a lot cleaner with less code and
less changes to existing parts of TF.
Of course not all resources are covered by this first release, but
there should be enough resources available to handle most common
operations.
Tests and docs are included.
