Rename ENV['PROTOCOL'] to ENV['GL_PROTOCOL'] to conform to what GitLab Shell expects and make the `protocol` param in `GitAccess` mandatory.

And create new Project#requesters, Group#requesters scopes.
Signed-off-by: NRémy Coutable <remy@rymai.me>

Feedback from:
https://gitlab.com/gitlab-org/gitlab-ce/merge_requests/4961#note_12794221

Closes #18949

And show information about locked status.

Help! This looks bad :o

The issue was with the `User#groups` and `User#projects` associations
which goes through the `User#group_members` and `User#project_members`.

Initially I chose to use a secure approach by storing the requester's
user ID in `Member#created_by_id` instead of `Member#user_id` because I
was aware that there was a security risk since I didn't know the
codebase well enough.

Then during the review, we decided to change that and directly store the
requester's user ID into `Member#user_id` (for the sake of simplifying
the code I believe), meaning that every `group_members` / `project_members`
association would include the requesters by default...

My bad for not checking that all the `group_members` / `project_members`
associations and the ones that go through them (e.g. `Group#users` and
`Project#users`) were made safe with the `where(requested_at: nil)` /
`where(members: { requested_at: nil })` scopes.

Now they are all secure.
Signed-off-by: NRémy Coutable <remy@rymai.me>

Also, reuse partials from the non-admin views.
Signed-off-by: NRémy Coutable <remy@rymai.me>

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

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

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

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

This reverts commit 13e37a3e.

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

Add a new application setting, after_sign_up_text. This is text to be
rendered as Markdown and shown on the 'almost there' page after a user
signs up, but before they've confirmed their account.

Tweak the styles for that page so that centered lists look reasonable.

This reverts commit 3e991230.

# Conflicts:
#	app/models/project.rb

This ensures all these calls have an author set, allowing the use of
"all" mentions where possible.