49ers announce 17 undrafted rookie signings

The San Francisco 49ers don’t open rookie minicamp until the end of next week, but they took time out Friday to announce the addition of 17 undrafted rookie signings. The Niners’ UDFA class for 2012: Northern Illinois fullback Cameron Bell, Clemson linebacker Kourtnei Brown, Wisconsin defensive tackle Patrick Butrym, Michigan State tight end Garrett Celek,…