It’s a measure of how much professional rugby players love playing rugby that there’s only ever been a handful that have quit while still at the top of their game. In Ireland only Denis Hickie, Keith Wood and now CJ Stander have managed it. Not many players communicate, verbally or non verbally, how much they love playing. But in his body language, his zest for contact, his smile, his non stop pep talks to teammates and his almost palpable desire, Stander stands out.  He’s not a gifted player that was always going to make it; he left South Africa because…