encourage end-users to download the official release, not the prerelease 

The current download page lists the 0.3 prerelease *first*, and then the 0.2 release.  I think this is a bad idea, because it means that most users end up downloading the prerelease, without realizing that they are getting an unstable snapshot.    This patch lists the current release first, then the prerelease, and warns the user that it is a nightly snapshot whose usability may change from day to day.

This has bitten me over and over again when working with students; it is a huge problem when whether something works depends on what *day* the student downloaded it.   People just don't realize that not all prerelease snapshots are the same.

Encouraging users to download the prerelease was probably a good idea a year ago, when the prerelease was probably far less buggy than the release version, but I don't think the benefit is great enough now to foist unstable snapshots on unsuspecting users.