Design new Notifications view and Selections view

[Bad-Science]

We are finally going to implement the event/notifications system!

But first, we need to figure out how this fits into the UI. This issue will build off of the work presented in #34 to find a layout and design that accommodates both a selections view and a notifications view in an elegant way.

The primary purpose of this issue is to serve as a thread for posting and discussing design ideas, soliciting feedback, and reaching a final design.

This issue can be closed when the design has been finalized.