[EE] fix label and issuable referencing in epics

Closes #5390

See merge request gitlab-org/gitlab-ee!5205

* `~label` references are replaced with links to epics with this label
* cross-reference system note is created when an issuable is
referenced in a epic note (or when an issuable references an epic)

Related to #5390

Geo: Respect retry_at when downloading artifacts

Closes #5560

See merge request gitlab-org/gitlab-ee!5239

CE upstream - 2018-04-05 09:32 UTC

See merge request gitlab-org/gitlab-ee!5245

Add custom additional text to emails

Closes #4474

See merge request gitlab-org/gitlab-ee!5031

Update Geo nodes layout for better usability

Closes #5146

See merge request gitlab-org/gitlab-ee!5199

New Crowdin translations

See merge request gitlab-org/gitlab-ee!5241

# Conflicts:
#	.gitlab-ci.yml
#	app/assets/javascripts/boards/services/board_service.js
#	app/helpers/services_helper.rb

[ci skip]

Changed IDE sidebar min width

Closes #44836

See merge request gitlab-org/gitlab-ce!18123

Merge security fixes to master

See merge request gitlab/gitlabhq!2369

Export and import LFS objects

Closes #40643

See merge request gitlab-org/gitlab-ce!18115

Move ListCommitsByOid to OPT_OUT

See merge request gitlab-org/gitlab-ce!18175

CE upstream - 2018-04-05 05:20 UTC

See merge request gitlab-org/gitlab-ee!5240

This makes accessing LFS Objects for a project easier

  project.lfs_storage_project.lfs_objects`

becomes

  project.all_lfs_objects

This will make the refactor in
https://gitlab.com/gitlab-org/gitlab-ce/issues/39769 easier to deal
with.

Downloading the stream directly to the archive. In order to avoid
conflicts with the cache.

If the LFS object already exist, we'll link it tot he existing one, if
not we'll create it.

The LFS files will be included in the `lfs-objects` directory in the archive.

Fix 404 in group boards when moving issue between lists

Closes #44551

See merge request gitlab-org/gitlab-ce!18064

EE-PORT Fix 404 in group boards when moving issue between lists

See merge request gitlab-org/gitlab-ee!5217

Fix https://gitlab.com/gitlab-org/gitlab-ee/issues/4474

Update issue_board.md to fix one occurrence of the Gitlab edition for multiple issue board feature

See merge request gitlab-org/gitlab-ee!5189

Signed-off-by: Rémy Coutable <remy@rymai.me>

[Rails5] Add rails5 jobs to gitlab-ci.yml

See merge request gitlab-org/gitlab-ce!18163

[Rails5] Add rails5  jobs to gitlab-ci.yml

See merge request gitlab-org/gitlab-ee!5236