Add a bartik based layout plugin to the bartik theme

This is a first pass at this that I mostly stole from sdboyer's excellent patch over on #1812720: Implement the new panels-ish controller [it's a good purple]. I figured I could try to push in smaller components of what he's doing that should be relatively non-controversial. This is a first pass, and some portions that shouldn't be in a layout plugin are still there. Anything that's not a full fledged region needs to be address and either removed, or replaced with a region (depending upon whether it sits in a portion of the template that a region couldn't just as easily fulfill. breadcrumbs is a good example of something that will likely need a custom region).

This is throwing a few errors still, but we need to address the functionality that's trying to provide in any event, so I didn't try to fix it yet.

Eclipse