Many Repo Fixes -- EE merge edition

See merge request !2679

CE Upstream - Monday

Closes #3121, gitlab-ce#31706, gitlab-ce#36066, and gitlab-ce#31698

See merge request !2674

Document creating new issue from the group-level Issue Tracker.

Closes gitlab-ce#36375

See merge request !2687

EE counterpart for CE MR !13360

See merge request !2675

Conflicts:
	app/assets/javascripts/repo/components/repo_edit_button.vue
	app/assets/javascripts/repo/components/repo_editor.vue
	app/assets/javascripts/repo/components/repo_tab.vue
	app/assets/javascripts/repo/components/repo_tabs.vue
	app/assets/javascripts/repo/helpers/repo_helper.js
	app/assets/javascripts/repo/services/repo_service.js
	app/assets/javascripts/vue_shared/components/popup_dialog.vue
	app/assets/stylesheets/pages/repo.scss
	app/views/shared/repo/_repo.html.haml
	spec/javascripts/repo/components/repo_edit_button_spec.js

Introduced in
https://gitlab.com/gitlab-org/gitlab-ce/commit/715ecfab2f6b34d77e206859a95eae269e4c0d52

Introduced in
https://gitlab.com/gitlab-org/gitlab-ce/commit/e9f557054869772955f86de3ac8138c7fc020564

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

getContent was called for the file and the directory it was in causing
`isTree` to change to `true`. Then when you went to edit the file, it
was still `true`.

Conflicts:
	app/assets/javascripts/repo/components/repo.vue

Fix ConnectionProxy#method_missing for trailing hash arguments

Closes #3166

See merge request !2682

EE: Refactor how we fetch ref for merge requests

See merge request !2665

Fix
https://gitlab.com/gitlab-org/gitlab-ce/merge_requests/12198#note_37146854

Conflicts:
	app/assets/javascripts/repo/helpers/repo_helper.js

Fix
https://gitlab.com/gitlab-org/gitlab-ce/merge_requests/12198#note_37147332

Conflicts:
	app/assets/javascripts/repo/stores/repo_store.js

Fix
https://gitlab.com/gitlab-org/gitlab-ce/merge_requests/12198#note_37146815

See https://gitlab.slack.com/archives/C0GQHHPGW/p1501779964878178

Fix
https://gitlab.com/gitlab-org/gitlab-ce/merge_requests/12198#note_37146360

Conflicts:
	app/assets/javascripts/repo/components/repo_edit_button.vue

Fixed value could potentially be not enough

Fix
https://gitlab.com/gitlab-org/gitlab-ce/merge_requests/12198#note_37145886

Fix
https://gitlab.com/gitlab-org/gitlab-ce/merge_requests/12198#note_37145729

Fix
https://gitlab.com/gitlab-org/gitlab-ce/merge_requests/12198#note_37145640

Fix
https://gitlab.com/gitlab-org/gitlab-ce/merge_requests/12198#note_37144070

Fix
https://gitlab.com/gitlab-org/gitlab-ce/merge_requests/12198#note_37143794

Fix
https://gitlab.com/gitlab-org/gitlab-ce/merge_requests/12198#note_37143710

Fix
https://gitlab.com/gitlab-org/gitlab-ce/merge_requests/12198#note_37143527

Conflicts:
	app/assets/javascripts/repo/components/repo_tab.vue

Fix
https://gitlab.com/gitlab-org/gitlab-ce/merge_requests/12198#note_37143217

Conflicts:
	app/assets/javascripts/repo/helpers/repo_helper.js

Fix
https://gitlab.com/gitlab-org/gitlab-ce/merge_requests/12198#note_37143174

Conflicts:
	app/assets/javascripts/repo/components/repo_sidebar.vue

Fix
http://192.168.1.135:3000/gitlab-org/gitlab-ce/blob/master/app/assets/javascripts/broadcast_message.js