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

Closes #13574

API issue update and note create back dating

Closes #14947 

See merge request !3551

Add test for search page

Closes #15222

See merge request !3711

Add ability to push to remote repositories

Closes #116 

See merge request !249

* Use Rugged filters to work with local/remote branches.
* Rename Project#remote_mirror? to Project#has_remote_mirror?
* Use delegate pattern for Repository#push_remote_branches and Repository#delete_remote_branches
* Make Repository#remote_tags return Gitlab::Git::Tag objects.
* Refactor Repository#remote_branches
* Rename Repository#push_branches to Repository#push_remote_branches
* Made other small refactors to views and specs.
* Make encrypted_credentials column size bigger.
  This was giving problems with MySql for large passwords.
* Refactor for UpdateRemoteMirrorService spec so we no longer
  harcode the branch names and specs are not broken after `gitlab-test`
  project is updated.

* Also fixed couple of small bugs introduced with last changes

* Also addressed feedback from https://gitlab.com/gitlab-org/gitlab-ee/commit/fcbfe56207f64da07deb7f3a8cbdcd505069edbd

* Now #url= and #url always handle the full URL, encryption is done transparently
* #safe_url was added for future purposes
* Little refactor for UpdateRemoteMirrorService

* Also added small fix for the scenario when the remote repo is empty
 and does not have tags.

* Add the ability to skip tags when fetching a remote repo.
  See: https://gitlab.com/gitlab-org/gitlab-shell/merge_requests/46

Merge branch 'regression-ldap-group-synchronization-is-broken-for-our-company-s-ldap-with-gitlab-8-6-442' into 'master'

Fix LDAP group sync regression for groups with member value `uid=<username>`

Closes #442 

See merge request !335