Closes#3940
- Pushing left/right changes the "focus" of the posts screen to the list / content, respectively
- Once one of these has been focused, up/down keyboards work on that section in particular
- By default, the post list is selected
- Using the keyboard to focus one of the two makes it go "poof" to let you know you changed stuff
Closes#4186, Closes#4190, Closes#4150
- Alters markup to allow for correct use of `-webkit-overflow-scrolling: touch;`
- Updates the debug page to use the same markup as the rest of the settings page
- Solve floating tag bar issue by making it absolute, not fixed
Closes#4032
- Created "mobile" views: `parent-view`, `content-view` and `index-view`
- `mobile/parent-view` has three callbacks for managing layout, and a mediaQuery listener to keep in sync with the user
- content-view and index-view use their parent-views callbacks to bring themselves into and out of the viewport as appropriate
- fixed media queries for post content list from 800px to 900px
- Created `mobile-index-route` to intelligently transition to a new route on desktops (used by both PostsIndexRoute and SettingsIndexRoute)
- Extract mobile interactions from settings views to new mobile utility views
- `js-` prefixed settings view transitions
- removed unused openEditor action from PostsRoute
- removed unused mobile util "responsiveAction"
