Add support for getting review request drafts via JSON

Review Request #614 — Created Oct. 26, 2008 and submitted — Latest diff uploaded


Review Board SVN (deprecated)


My IDE plugin now supports updating existing review requests. In order to do this nicely, I made it so that it can fetch existing drafts to update them. But there currently isn't a JSON API for getting the draft of a review. This little patch adds that support.
I fetched lots and lots of drafts while developing my plugin.