NFL: San Francisco 49ers Transactions, News, and Rumors New Additions Signed RB Brian Westbrook (1 year, 1.25 million) Signed QB David Carr (2 years, 6.175 million) Signed LB Travis Laboy (1 year, 1.6 million) Signed QB Troy Smith (1 year, TBA) T Alex Boone (reserve/future contract) Cuts QB Nate Davis QB Jarrett Brown RB Michael…