Mattress Firm Holding Corp (NASDAQ:MRFM) is soaring and with it taking many shorts up to heaven or if they have been naughty taking them down. The stock is a big short favorite with about 40 percent of the share held short, and we too recently featured a short write up on the stock from a guest contributor. The stock is up about 115 percent on a massive takeover bid from Steinhoff in a $2.4 billion deal. What are the details? Below is what the sell side is saying. Mattress Firm Holding Corp Wedbush Steinhoff is a vertically integrated, diversified international mass market…