The 49ers will want to get a speed wide receiver this offseason, someone who can finally stretch defenses.They'll also be in the market for a cornerback, backup quarterback and defensive end. But perhaps the most important item on the franchise's to-do list this offseason is to extend the contract of head coach Jim Harbaugh.When Harbaugh left Stanford in 2011 to take the 49ers job, he signed a five-year, $25 million deal. Now, there are two years remaining on that contract.If the Niners don't extend him, the prospect of Harbaugh leaving San Francisco might start to pop up more often in 2014 and beyond. Even this past season, when the University of Texas coaching job became vacant, Harbaugh had to answer questions about his interest in it. In December, when reports attributed to an unnamed source surfaced that Harbaugh had talked with Texas, Harbaugh denied he had any intention of leaving, and said he wants to stay with the Niners."Rumors? Give me evidence. … Any evidence," he said. "What are we talking, hearsay here? Well in Judge Judy's court, hearsay is not admissible evidence. I think we can all agree that an unnamed source is hearsay. Would we not?"Added Harbaugh:...