Colin Kaepernick's stock is skyrocketing in the National Football League - and he's moving the needle on sales of San Francisco 49ers team jerseys and memorabilia as a result.Kaepernick, the 49ers' second-year quarterback who led the University of Nevada, Reno, football team to one of its best seasons ever in 2010, proved his mettle in the NFL with several big wins - including a thrilling win over the New England Patriots in a nationally televised game barely more than a week ago.Sales of his No. 7 team jersey increased 4,000 percent since he was named a starter, says Josh Feinstein, …