This is kind of ridiculous, but I think it's still a bug and I do need help.
So I updated to Jenkins 1.656 to 2.0, and after the main war file got installed and restarted there was a nice button, I don't remember what it said, that in effect triggered installation of the basic package of plugins, or whatever you call it, the "out of the box" stuff. But due to high demand on the website most of them failed to install, and there seems to be no way to try again. How do I get that button back, or, short of that, just a direct link or script to get all those plugins at once? I have no idea what they were because I tried rolling back and reinstalling but the button is still gone.