* native http: new restconf_err files, generic data input, restconf_methods generalized. * test: expecteq removed.
* All uses of `api_path2xpath_cvv()` should be replaced by `api_path2xpath()` * `api_path2xpath()` added an `xerr` argument.
* `201 Created` for created resources * `204 No Content` for replaced resources. * See [RESTCONF: HTTP return codes are not according to RFC 8040](https://github.com/clicon/clixon/issues/56) * HTTP `Location:` fields added in RESTCONF POST replies