* Add variables for text colors

* Change variables in sass files

* Apply text color variables for recently added colors

* Fix text colors of emoji mart anchors

* Fix text colors of search__input

* Fix text colors of text area of compose-form

* Fix icon colors of privacy dropdown and modal

* Inverted icon colors by classname

* Change variables in boost.scss

* Change action-button-color

* Fix text colors of pre-header

* Make dropdowns render into portal, expand animation

* Improve actions modal style

* Refactored Avatar and AvatarOverlay (DRY) to have 'account' as prop.
Also removed animate attribute from compose navigation bar, which should
have never been there. Added test for avatar overlay.

* fix broken tests

* god dammit another bug in tests! travis please let this pass

* formatting in avatar overlay

* fix(dropdown_menu): Keyboard navigation

* fix(icon_button): Add aria-pressed attribute

* fix(privacy_dropdown): Make accessible

* fix(emoji_picker_dropdown): Make accessible

* fix(icon_button): Support tabIndex

* fix(actions_modal): Remove icon from tab order

* fix(dropdown_menu): Add role=group

* fix(setting_toggle): Toggle via space key

* fix(dropdown_menu): Remove redundant handling of Space key

* fix(emoji_picker_dropdown): Remove redundant Space key handling

* fix(privacy_dropdown): Remove redundant Space key handling

* fix(status): Switch to article and add aria-posinset, aria-setsize

* fix(status_list): Use role=feed and pass more ARIA props to Status

* chore(eslint): jsx-a11y/role-supports-aria-props

* fix(dropdown_menu): Open as modal on mobile

* fix(dropdown_menu): Open modal on touch

* fix(dropdown_menu): Show status

* fix(dropdown_menu): Max dimensions and reduce padding

* chore(dropdown_menu): Test new functionality

* refactor: Use DropdownMenuContainer instead of DropdownMenu

* feat(privacy_dropdown): Open as modal on touch devices

* feat(modal_root): Do not load actions-modal async