Fix displaying screenshot draft captions.

Review Request #2337 — Created May 4, 2011 and submitted


Review Board


Fix displaying screenshot draft captions.

Screenshot draft captions weren't displayed on the review request page.  We
were only showing the main caption. We now look to see if there's a draft, and
if so, we try to pull that out.

We also update the draft's timestamp when saving a screenshot, in order to bump
the Last Modified time for the page. Without this, it'd take a shift-reload in
order to see the new caption.
Newly edited captions were reflected on the page, and persisted after reload.