CI setup doc

I want do describe what CI services we use

See merge request !1099

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

Security in dvcs

Explain why access & sharing are the same.

See merge request !1097

remove rack attack middleware update

Hasn't changed since 7.2 release: https://github.com/gitlabhq/gitlabhq/commits/master/config/initializers/rack_attack.rb.example

Document the extra.sign_in_text setting for CE

See merge request !1027

Check for hooks directory symlink in gitlab:check

See merge request !1094

Dont rebase pushed commits

/cc @jacobvosmaer

See merge request !1095

Add dormant New Relic gem

See merge request !1089

The gem can be enabled and configured via environment variables.

API MR ordering

Fixes #1477

See merge request !1076

Use sockets to connect to Redis

See merge request !1088

Implement comments on parallel diff

Fixes #1565

See merge request !1090

Fix grammatical error in 'not merged changes' msg

Update user_management.md

Adding ability to configure webhook timeout via gitlab.yml

[Refactor] Remove duplicated labels step

formatting changes, table->database

Use the default Unicorn socket backlog value: 1024

See merge request !1087