New mirror update... decisions, decisions.

I've been on -current so long that it was a surprise to see the new mirror update.

14.2 gone, 15 is stable, and Slackware64 is the new dev branch.

I used to think I'd just jump onto 15 stable, but now I'm so used tracking -current, I just uncommented the new dev branch instead.

I may switch one other device to stable, but aside from the rare bump, I kinda want to stay on dev.