Panels 2.0, alpha 10

I added arguments to this one. There's a pretty sweeping change here, partly in that it's doing ajax outside of the main content area; partly in that I re-organized the file structure rather a lot; and partly in that I opened things up. A lot.

My brain is pretty wiped so I'm having trouble describing what I did, but in my mind it is totally full of awesome.

Remaining TODO list before I can call this a beta:

o finish argument for taxonomy
o finish content types for taxonomy
o argument for user
o content types for user
o allow mini-panel to accept arguments
o Allow views to correlate arguments to panels contexts.
o include some more interesting styles
o allow panel page to use the styles
o Some ajax code cleanup
o Some argument code cleanup
o Clone panels page feature
o Some other cleanup with the drag & drop that you notice unless you're reading the code

My guess is this is less stable than the last alpha. A lot went into this and I trudged pretty hard through some stuff that was being a little frustrating. I still have tons of cleanup to do, there are some places where I'm really unhappy with the code.

But we're getting close to a beta. It's possible there won't even be another alpha release if I can get all of that done next week. A few of those things can be done by other people, too, if anyone wants to volunteer.