Updated the Front Page

I doubt what I've done will really be a raging controversy but I stuck it here anyway.

I've updated the front page, as you can probably tell by now if you're even reading this. I've taken the basic philosophy of the skin and used a 'dashboard' to create a page with multiple content areas, and plugged content in accordingly (with a tiny bit of PHP code to do so). Hot stuff can go in the sidebar. Right now it'll only show up on the front page but we can easily turn that on in a lot of places, depending on where we want that to go.

I've also done my best to get everything else out of the sidebars so that we don't have to use screen real estate on them, and now sidebars can be entirely content-driven. The front page is basically kind of a proof-of-concept. The dashed boxes are indicative of "someone who knows more than Merlin about how boxes on this site should look should hit style.css and go to town."

I did something similar with the Development stuff. The Wiki is still accessible tho if you don't know where the menu moved to it might be hard to find. (It'll turn up under 'developers' when you click on it).

There's a few broken things in 4.7 still, so some of the horizontal menus are a little wrong, and apparently the rollups are broken on node/add for some reason.