Add a global side draw system in the admin


Something along the lines of the slider here: (the + icon on the right hand side).

What would be useful is to be able to define this sidebar independantly from the admin page logic. Applications should be able to customize the content of this bar by adding global options or options specific to the page that you are viewing. We could/should move alot of the items that we currently place at the top right of a page to this sidebar for better use of space, consistency and more flexibility.

Ideas around what we could do around this welcomed!