Diary "draft" mode

[dalek2point3]

Would it be possible to add a "draft" mode to the diary entries? At the moment, its hard to write blog posts over many days -- and to make matters worse, as soon as a diary entry is published it shows up on http://www.openstreetmap.org/diary implicitly publicizing a post even if it's half done.

I'm not familiar with the codebase, and perhaps this issue has been requested before, but I thought I'd put this feature request out there.