Add documentation for "status" field in Confluence REST API docs

In order to fetch a previous version of a page using the Confluence REST API, you need to specify 'status=historical' in the query parameters. Although the "status" parameter is mentioned in the REST API docs, there is no where a list of the status values and what they mean.

The REST API docs should really just list out the valid values for "status" and what they mean.

There is no way from reading the documents to guess that "status=historical" is needed when attempting to fetch a historical document. All the user gets is a "501 Not Implemented" error when this parameter is left out. Someone suggested (see link below) that in the past the error message in this case was more helpful than it is currently.

See: https://answers.atlassian.com/questions/35779624/is-fetching-of-previous-versions-of-a-wiki-page-really-not-implemented-in-the-confluence-api