EE- Remove scss variables, part 2

See merge request gitlab-org/gitlab-ee!6887

CE upstream - 2018-08-13 21:22 UTC

Closes gitlab-ce#50210

See merge request gitlab-org/gitlab-ee!6888

Resolve "Customize notifications for new epic - Web and API"

Closes #5863

See merge request gitlab-org/gitlab-ee!6626

EE: Change `Backlog` list title to `Open` in Issue Boards

See merge request gitlab-org/gitlab-ee!6884

These are dynamic translations, so has to be marked explicitly using `N_`,
but they are not used in runtime, so can exist in separate file.
https://github.com/grosser/gettext_i18n_rails#unfound-translations-with-rake-gettextfind

Remove https from Snowplow Collector URI placeholder in Admin Area

See merge request gitlab-org/gitlab-ee!6886

This way we can globally set group only ee events too.
Use nil to indicate global.

Add email_events to replace EMAIL_EVENTS because it needs to be dynamic,
allowing override for EE group to add new_epic event.

# Conflicts:
#	doc/user/project/quick_actions.md
#	locale/gitlab.pot
#	spec/services/quick_actions/interpret_service_spec.rb

[ci skip]

Bump rugged to 0.27.4 for security fixes

See merge request gitlab-org/gitlab-ce!21170

CE upstream - 2018-08-12 18:21 UTC

See merge request gitlab-org/gitlab-ee!6881

Add Noto Color Emoji font support

See merge request gitlab-org/gitlab-ce!19036

See https://github.com/libgit2/libgit2/releases for more details.

This is a font from [Google](https://www.google.com/get/noto/).

Arch Linux [has a recommendation of it](https://wiki.archlinux.org/index.php/fonts#Emoji_and_symbols).

Add info about this into `docs/user/markdown.md#emoji`

Added docs for Web IDE Client Evaluation

Closes #50143

See merge request gitlab-org/gitlab-ce!21155

Improve visuals of language bar on projects

See merge request gitlab-org/gitlab-ce!21006

Resolve "`Copy to Clipboard` tooltip appears under modal"

Closes #41996

See merge request gitlab-org/gitlab-ce!21017

port "copy to clipboard tooltip appears under modal" to EE

See merge request gitlab-org/gitlab-ee!6877

Protocol is configured using the forceSecureTracker option during
tracker initialization which is enforced anyway.

Fixed small scroll area in Web IDE

Closes #50242

See merge request gitlab-org/gitlab-ce!21160