In emails-on-push message, indicate message that individual file diff is too large

If a single file exceeded a diff limit, the previous implementation would just include the file as changed but the diff itself was not shown, leading to confusion:

![image](/uploads/18cd8e6b5c571305927097e1baf6097d/image.png)

Notice how the `nodes.pp` line shows no changes.

Diff overflow limits apply to different cases:

1. The entire diff exceeds 100 files OR 5000 lines
2. One single file exceeds 100 KB

Example case 2: Let's say we have a diff of 50 files, most of them under 100
KB, but one of them over that limit. In this case, the idea of
gitlab-org/gitlab-ce!2705 is that GitLab should show the diff of the 49 files
but omit the last one.

New screenshot:

![image](/uploads/9a0ac68e3deb08c28cab032fbbb80c9f/image.png)


See merge request !340

Diff overflow limits apply to different cases:

1. The entire diff exceeds 100 files OR 5000 lines
2. One single file exceeds 100 KB

Example case 2: Let's say we have a diff of 50 files, most of them under 100
KB, but one of them over that limit. In this case, the idea of
gitlab-org/gitlab-ce!2705 is that GitLab should show the diff of the 49 files
but omit the last one.

Geo: Use System Hooks for key synchronization

This MR changes from our custom notification solution to use system hooks instead for GitLab Geo (#76).
We had also to change the way we authenticate API requests for Geo. (See !334 for reference).

With new implementation, we create one system hook for every secondary Geo Node, and there will be a single endpoint that will receive all events (more to be migrated to System Hook).

See merge request !332

See merge request !331

Concat AD group recursive member results with reguler member results

Closes #484 



See merge request !333

Use rake db:reset instead of db:setup

See merge request !3721

Using db:reset ensures existing tables are first dropped. This in turn
ensures that we can drop tables regardless of any foreign key
constraints. While CE currently doesn't have any foreign keys EE defines
the following relation:

    remote_mirrors.project_id -> projects.id

MySQL will complain whenever you try to drop the "projects" table first
even when using "DROP TABLE ... CASCADE".

Start with iid on branch creation

After the discussion it in #3886 it was decided the iid should be in the beginning of the branch name.

See merge request !3708

Update shibboleth configuration for GitLab 8.6 and Apache 2.4



See merge request !3713

Add TOC to yaml README and an intro section



See merge request !3719

[ci skip]

Fix emails on push diff limit

The diff limits were not respected in the emails-on-push since the refactoring in gitlab-org/gitlab-ce!2705. This was one possible cause for customer issue described in gitlab-org/gitlab-ce#15137.

This MR also brings in the changes in !337 since they are required for this to work.


See merge request !338

Added highlight colours to diff rows

Closes #13852

Refactor and expose only Gitlab::UrlBuilder.build(record)

```
$ git grep Gitlab::UrlBuilder

app/models/commit.rb:      url: Gitlab::UrlBuilder.build(self),
app/services/issues/base_service.rb:      issue_url = Gitlab::UrlBuilder.build(issue)
app/services/merge_requests/base_service.rb:      hook_data[:object_attributes][:url] = Gitlab::UrlBuilder.build(merge_request)
app/views/search/results/_note.html.haml:- note_url = Gitlab::UrlBuilder.build(note)
lib/gitlab/note_data_builder.rb:        base_data[:object_attributes][:url] = Gitlab::UrlBuilder.build(note)
spec/lib/gitlab/note_data_builder_spec.rb:    expect(data[:object_attributes][:url]).to eq(Gitlab::UrlBuilder.build(note))
spec/lib/gitlab/url_builder_spec.rb:describe Gitlab::UrlBuilder, lib: true do
```

Fixes #15202.

See merge request !3696

Note form

A lot of the forms have the same actions associated with them so I have created a standard class that encapsulate these actions.

There is also another class that allows toolbar action buttons to be added that will insert different characters based on the HTML `data-prefix` attribute value - this will give us the opportunity to add more actions to the form and maybe create a markdown toolbar in the future.

See merge request !3534

Updated JS spec to include gl_form

Updated the JS to have a standard class with standard actions for each form
Created ability to have toolbar buttons that insert different prefixes dependant upon the data-prefix attribute

Do not require recipients when pusher will be recipient

Closes #10946

See merge request !3603