Previously: Martin Prince, the Queen of Summer. The world owes a great deal to minor Simpsons characters, and I have taken it upon myself to periodically-yet-irregularly celebrate them as the spirit moves me. Today we honor Ralph Wiggum. There is no place on the social structure for a second-grade boy who thinks rats are "pointy kitties" and calls his teacher "Mommy." Kids can be misfits (Milhouse), or they can be brownnosers (Martin), or they…