Analysts’ upgrades for Thursday, April 4th: Aviat Networks (NASDAQ:AVNW) was upgraded by analysts at StockNews.com from a sell rating to a hold rating. American Express (NYSE:AXP) was upgraded by analysts at StockNews.com from a hold rating to a buy rating. AutoZone (NYSE:AZO) was upgraded by analysts at StockNews.com from a hold rating to a buy […]