Unset extending under top and bottom bars for all view controllers.

Turns off extending under top and bottom bars for all views. While not the best solution, it does address #185.

I couldn't come up with a good way to set all navigation bars and toolbars as opaque, so they are a dismal shade of gray now :(. I'll look at making the bars white again soon, and add to this PR.

Fixes #185, but makes the app all gray.

Update: I turned off translucency for navigation bars and toolbars using a navigation controller subclass. They appear white again.