Refactor settings routing and mobile interactions

Closes #3254, closes #3138, closes #3245
 ### Settings Routing and View refactoring
- Refactored `SettingsView` to handle transitions between mobile and desktop layouts
- `SettingsRoute` will only transition to `settings.general` if the screen is large enough to show both the menu and the content
- Added `SettingsIndexView` to handle showing the settings menu on mobile screens
- Added `SettingsContentBaseView` to be inherited by any settings view that is not index.
- Updated Settings templates appropriately to work with new views
- Removed extraneous `active` class from `settings-content`
- Changed settings menu to use `gh-activating-list-item`
- Retooled settings tests

 ### Mobile Utils
- Renamed file to `mobile.js`, since it's inside of `utils/`
- Added `mobileQuery` MediaQueryList to help detect layout changes
- Removed unused `hasTouchScreen`, `device.js` should be used instead.
- Removed unused `smallScreen` function
- Moved FastClickInit to codemirror-mobile
Remove minor notifications; Close persistent notifications even on error

Closes #3105, Closes #3175

- Removed notification on successful post's `page` status change
- Removed notification on successful post `featured` status change
- Added `closePassive()` notifications on error in the post-settings-menu
- Persistent notifications will close whether their `DELETE` request was
  successful or not.

 #### Misc
- Added `name` attribute to `post-setting-menu.hbs` inputs to facilitate testing
- Removed `return <Promise>` from action in `PostSettingsMenuController`. Actions should only return `true`
- Toggling `post.featured` won't fire NProgress.
Merge pull request #3210 from novaugust/remove-minor-notifications

Remove minor notifications; Close persistent notifications even on error
Merge pull request #3259 from novaugust/settings-mobile-routing

Refactor Settings routing and mobile interactions
Replace anchors with no real href with buttons

Closes #3101 & #916