There is a sound college football makes before it makes any noise at all: the low, percussive grunt of a three-hundred-pound man exhaling through his nose as he drives another three-hundred-pound man backward into a blocking sled, the way a mule might argue with a plow and lose. I have heard that sound most mornings this week out at the Cougars' practice fields, coming with some regularity now from the direction of a young man named Shadre Hurst, and I have come to think of it as one of the more honest sounds in sports, because nobody ever grunted like that for a highlight reel. Hurst, a…