shibboleth authentication support

Wrap by default for parallel

Fixes #1566

See merge request !1080

Update gitlab-grit to 2.6.11

See merge request !1081

From the gitlab-grit changelog:
  * Suppress 'unkown header' warnings
  * Add process.out to CommandFailed error

Update omniauth-ldap and net-ldap

See merge request !1077

Revert "Delete mailer queue"

Use canonical repos

/cc @dzaporozhets

See merge request !1079

Fetch the testme repository from gitlab.com

See merge request !1078

The repository was removed from github.com/gitlabhq.

add bunder step to mysql_to_postgresql doc

added documentation for shibboleth omniauth provider
updated changelog

fix formatting issue in installation guide

fix formatting issue with self-signed certificate section

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

Parallel diff refactor

Refactor side-by-side diff to remove code duplication.

Base the side-by-side diff on inline diff code.

In first iteration:

1. commenting on the side-by-side diff is not possible
1. no expanding of the surrounding code

See merge request !1066

Added search wiki feature

Wrap arguments for `[ -z` in double quotes

See merge request !1071

Add ci to blacklist

See merge request !1075

Close button after added comment

Fixes #1549

See merge request !1070

API: Project create docs miss path argument

Fixes #1551

See merge request !1074

Refactor diffs

This refactoring done on top of Marin improvements to side-by-side diff.
Main target of this refactoring is to reduce mess and increase test coverage.

1. Use objects:
  * Gitlab::Diff::Line for line change in diff
  * Gitlab::Diff::File for file changes (diff + blob info)
2. Avoid `yield` magic
3. Move logic from views/helper to models/libs
4. Move diff views under separate dir `app/views/projects/diffs`

See merge request !1072

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

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

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

Adding in snippet search functionality

Fix images on github

Fixes https://dev.gitlab.org/gitlab/organization/issues/55

/cc @job @dzaporozhets

See merge request !1073

Conflicts:
	CHANGELOG