7 6 2 ee packages

The older packages are just moved down instead of sorted. This makes it easier for the person releasing and easier to find the right version.

See merge request !273

Packages update for 7.6

See merge request !272

Update Documentation for 7.6 release

Updated install and update docs for 7.6-ee release.

See merge request !271

Group membership lock

Fixes gitlab/gitlabhq#1591

See merge request !268

Conflicts:
	db/schema.rb

Changes from CE 7.6

See merge request !270

Kerberos support

https://dev.gitlab.org/gitlab/gitlabhq/issues/1414

Ability to login using kerberos credentials

![Screen Shot 2014-12-12 at 21.06.01](https://dev.gitlab.org/uploads/gitlab/gitlab-ee/cdc0fb7ee9/Screen_Shot_2014-12-12_at_21.06.01.png)

Ability to attach kerberos account

![Screen Shot 2014-12-12 at 21.19.23](https://dev.gitlab.org/uploads/gitlab/gitlab-ee/e926fb3798/Screen_Shot_2014-12-12_at_21.19.23.png)

See merge request !267

Conflicts:
	CHANGELOG-EE

Update changelog 7.6

See merge request !1327

Kerberos dependency

See merge request !1324

Fix note update

In some strange cases Ruby thinks `system` is not AR field but
Kernel.system call and raises exception during save. It should prevent
this random wierd behaviour.

Exception log:

```
ArgumentError (wrong number of arguments (0 for 1+)):
  app/models/note.rb:505:in `system'
  app/models/note.rb:505:in `editable?'
  app/controllers/projects/notes_controller.rb:33:in `update'
```

See merge request !1326

Update changelog

keep in mind that there is unmerged MR without updating changelog https://dev.gitlab.org/gitlab/gitlab-ee/merge_requests/268

See merge request !269

In some strange cases Ruby thinks `system` is not AR field but
Kernel.system call and raises exception during save. It should prevent
this random wierd behaviour
Signed-off-by: Dmitriy Zaporozhets <dmitriy.zaporozhets@gmail.com>

Added process for green tests

Signed-off-by: Jeroen van Baarsen <jeroenvanbaarsen@gmail.com>

Fixed a lot of already defined notices

Added Code of Conduct

Add missing webhook doc for tag event

Signed-off-by: Jeroen van Baarsen <jeroenvanbaarsen@gmail.com>