Use the settings modal as an example/testcase

Squashed commit of the following:

commit 3842f87986
Author: Surinna Curtis <ekiru.0@gmail.com>
Date:   Mon Jul 3 19:57:39 2017 -0500

    Fix some style issues

commit 08628a0234
Author: Surinna Curtis <ekiru.0@gmail.com>
Date:   Mon Jul 3 19:35:22 2017 -0500

    Improved styling and layout of select app settings

commit 1787a7c20f
Author: Surinna Curtis <ekiru.0@gmail.com>
Date:   Mon Jul 3 17:13:53 2017 -0500

    remove the layout selector ui from the drawer

commit 7d93b180b1
Author: Surinna Curtis <ekiru.0@gmail.com>
Date:   Mon Jul 3 17:01:51 2017 -0500

    Add layout setting to app settings modal

- built in fullwidth styling
 - letterbox settings toggle
 - media no longer counts towards height when making toot-collapsing
measurements