Fix generating the path to the manual URL for dev builds.
Review Request #6579 — Created Nov. 12, 2014 and submitted
The old manual URL generation function was assuming that any non-released builds should us the 'dev' docs, but this is often wrong. What we actually want is to use the 'dev' docs for any X.Y.0 releases that aren't marked as "final". This changes the logic accordingly.
Tested different combinations of versions.
