[Bug 19377] Calculation of overall rating is misleading to users

https://bugs.winehq.org/show_bug.cgi?id=19377

--- Comment #7 from Rosanne DiMesio  ---
Often the outliers are correct. Ratings are specific to Wine versions, and very
few apps get more than one test report for any given Wine version. An app can
legitimately go from platinum to garbage due to a regression, and back up again
to platinum when the regression is fixed.