…mmits

Known problems:
* had to introduce `ResourceData.GetRawConfig()` since chef provisioner parses configuration manually;
* In `remote-exec` provisioner `inline` can no longer accept 'string' value, only list of strings allowed. - due to migration to schema. There's a workaround like it;s done in `chef` provisioner, but I'd like to keep code as is.

* `chef.Provisioner` structure left intact but now it's decoded from `schema.ResourceData` instead of `terraform.ResourceConfig` suing simple copy-paste-bsed solution;
 * Added simple schema without any validation yet;
 * `ResourceData.GetRawConfig` removed since it's not longer needed.