Version model seems unnecessary

Having a version attribute would imply many many copies of each version string stored in the database, one with each review. I think this could work if there isn't a list of available versions we can check, and we just need to believe the user when a vote is submitted about what version they're reviewing, but even then we could create a new SoftwareRelease (per ascii art above) on demand if somebody submits a review for a version we didn't have so far.

Anthony and I chatted about this bug a few days ago and from memory (Anthony can correct me :) ):

1) We'll remove the version Model
2) Currently just store the version string provided by the client on the review
3) Later, if we need more per-version functionality for reviews, we can update to use a postgres debversion column for comparisons and groupings etc.

Based on a comment by mpt on bug 686553 (related to stats, see comment 2), I actually think that we'll eventually need Anthony's original suggestion in the description, so that we can aggregate stats for:

 1) A software item
 2) A software item in a specific distroseries, and
 3) A software item of a specific version.

I don't know whether there should be a relationship between (2) and (3), or just both related to (1). In this case, the version string column (or debversion column) would just be on (3).