Encompasses designs from
 - https://gitlab.com/gitlab-org/gitlab-ce/issues/23206#note_43355199
 - https://gitlab.com/gitlab-org/gitlab-ce/issues/29985#note_30417407

This reverts merge request !14148

Revert "Merge branch '35012-navigation-add-option-to-change-navigation-color-palette' into 'master'"

This reverts merge request !13619

Fix inspired while working on
https://gitlab.com/gitlab-org/gitlab-ce/issues/32801

 - gl_emoji for falling back to image/css-sprite when the browser
   doesn't support an emoji
 - Markdown rendering (Banzai filter)
 - Autocomplete
 - Award emoji menu
    - Perceived perf
    - Immediate response because we now build client-side
 - Update `digests.json` generation in gemojione rake task to be more
   useful and  include `unicodeVersion`

MR: !9437

See issues

 - #26371
 - #27250
 - #22474

When rendering Asciidoc documents this merge request enables the diplay of
admonition blocks using font icons. This improves the looks of Asciidoc redered
files.

This uses the font-awesome fonts already present in Gitlab so no large
dependencies are required for this to work.

Closes #18661

This reverts commit 3e991230.

# Conflicts:
#	app/models/project.rb

As discussed in #15667.

Signed-off-by: NDmitriy Zaporozhets <dmitriy.zaporozhets@gmail.com>

This is a start on #3279 by updating the CSS for the dropdown menu. This doesnt include any CSS for the title bar or filter field

In an effort to get the JS file size down, i've removed NGProgress and replaced with TurboLinks own loading indicator

Ref #13820

Signed-off-by: NDmitriy Zaporozhets <dmitriy.zaporozhets@gmail.com>