I'm confused about some of the spoke terminology. Butted, double-butted. Guage numbers, what do they mean? What about guage numbers with a slash, such as 14/15? Alloy nipples and brass nipples. Stainless steel spokes, titanium spokes...any advantage there? Anodized spokes...does that have to do with only the color of the spoke, or is there some additional reason? Thanks.