Move dashboard code into it's own plugin and add some fallback dashboards.

If Dashboard plugin is not enabled -> Nodes index
If Dashboard and Nodes plugin is not enabled -> A empty page in the default Croogo plugin
Add a setupAdminDashboard event
Render dashboard boxes into two columns
Full width column on top
Trigger event before and after dashboard box render
Add dashboard table to save custom user dashboards
Rename controller to DashboardBoxes and add a model
Show some feedback on collapsing a dashboard box
Allow custom sorting of dashboard boxes
Save dashboard box location to database
Load up saved dashboard positions
Some pretty styling when dragging boxes around
Use a easy to remember constant for each column
Add an example dashboard block.