By Jamie Ross I was bent at the waist with Rebel's front left foot cradled in my lap. I was just tapping in the last couple of nails, replacing a shoe that had been click-clacking down the trail that afternoon, the footwear on his front feet looking more like flip-flops than horseshoes. Sweat dripped from my brow and ran into my eyes as I struggled with the weight of a 1,200-pound horse who was quickly losing patience with me. Tired of standing on three legs, he was leaning