Jim Harbaugh, Josh Johnson reunite, again

Two years ago, Colin Kaepernick and Josh Johnson were battling for the privilege of backing up starting quarterback Alex Smith in San Francisco. It didn’t seem all that outlandish at the time because:  (1) Kaepernick remained unproven; and (2) Johnson had played for coach Jim Harbaugh at the University of San Diego.  Kaepernick won the…