Jesus is part of the holy trinity, the father, son, and holy ghost. he's more than man, at least according to most christian dogma AFAIK. it was one of the big issues hammered out in the first council that decided what christianity was all about. some thought jesus was of god, and the others thought he was a man. the god-like crowd won out, since walking on water, curing leprosy, the immaculate conception, and all that other good stuff isn't something your average Joe Firstcentury could do.
i've never actually read the passage, but i'm pretty sure at the last supper he said one of his disciples would betray him. sounds like he knew what was going to happen. although i'm quoting History of the World: Part 1
so even if jesus got run over by a chariot in a busy street it would still be suicide since he knew it was going to happen. maybe that's how he got sent to hell, and rescued all the souls down there. since you can't exactly knock on the gate of hell and ask to be let in
edit - as for Martyrdom, can you quote a passage in the bible that says its ok? i'm not saying dieing in the service of God is suicide, even if you take on a thousand soldiers by yourself you can't foresee what will happen. but if you know all and see all, and end up dieing of anything other than "natural causes", it's suicide. Joan of Arc wasn't in the bible, she thought God spoke to her. sounds like schizophrenia to me