Clarify LDAP troubleshooting ldap_search example and align CE/EE docs [ci skip]

A customer noted an error/lack of clarity in the LDAP documentation
with the `ldap_search` example. Previously, if taken literally, the
customer may have expected the `$` variables to be automatically
replaced or if they paste the exact `user_filter` contents the
parentheses would have been incorrect. Let's just simply the filter
and use exactly what's in the configuration.

Also, this file was way out of wack between CE and EE. I synced them, except
for the banner at the top that links to EE LDAP docs on the EE side.

See merge request !877

A customer noted an error/lack of clarity in the LDAP documentation
with the `ldap_search` example. Previously, if taken literally, the
customer may have expected the `$` variables to be automatically
replaced or if they paste the exact `user_filter` contents the
parentheses would have been incorrect. Let's just simply the filter
and use exactly what's in the configuration.

Also, this file was way out of wack between CE and EE. I synced them, except
for the banner at the top that links to EE LDAP docs on the EE side.

Geo: fix a problem that prevented git cloning from secondary node

This MR prevents activity_service writing in secondary Geo (#76) node's database. This will fix the failure users were experiencing when trying to `git clone` from the secondary node.

cc @marin @dewetblomerus @patricio 

Closes #1243 

See merge request !873

[ci skip]

Refactor instructions for Geo docs

When I followed these instructions, it was hard to keep my place, or get a feel for how close I am to the beginning or the end, so I am trying to create a numbered list for the **Secondary Node** instructions, but doing formatting while keeping it as a list is proving to be really hard.

/cc @axil

See merge request !864

[ci skip]

[ci skip]

[ci skip]

[ci skip]

[ci skip]

[ci skip]

[ci skip]

[ci skip]

Add a note about LDAP nested group resolution.

For LDAP sync, nested groups must fall within the configured
`group_base`. A customer recently ran in to this issue. It's
not immediately obvious but at least we can make a note in the
documentation.

See merge request !872

For LDAP sync, nested groups must fall within the configured
`group_base`. A customer recently ran in to this issue. It's
not immediately obvious but at least we can make a note in the
documentation.

[ci skip]

[ci skip]

[ci skip]

[ci skip]

CE upstream

See merge request !871

[ci skip]

CE upstream

See merge request !867

Issue #13823: random message when all Todos are Done

## What does this MR do?

Shows a random message every time the To Do list is empty: https://gitlab.com/gitlab-org/gitlab-ce/issues/13823

## Are there points in the code the reviewer needs to double check?

It's my first contribution to GitLab so I might need some help:

 - I'm loading a yaml file in the controller. I'm not sure where would be the best place to put it.
 - I'm also having the error below running the tests but it doesn't seem related to my changes. I think I might have some issue with my config. Could you double check if the tests pass for you?

/home/pep/.rvm/gems/ruby-2.3.1/gems/actionpack-4.2.7.1/lib/action_dispatch/middleware/debug_exceptions.rb:21:in `call': No route matches [GET] "/autocomplete/users/sjobs@apple.com.json" (ActionController::RoutingError)

## Why was this MR needed?

https://gitlab.com/gitlab-org/gitlab-ce/issues/13823

## Screenshots (if relevant)

## Does this MR meet the acceptance criteria?

- [x] [CHANGELOG](https://gitlab.com/gitlab-org/gitlab-ce/blob/master/CHANGELOG) entry added
- [ ] [Documentation created/updated](https://gitlab.com/gitlab-org/gitlab-ce/blob/master/doc/development/doc_styleguide.md)
- [ ] API support added
- Tests
  - [x] Added for this feature/bug
  - [ ] All builds are passing
- [x] Conform by the [merge request performance guides](http://docs.gitlab.com/ce/development/merge_request_performance_guidelines.html)
- [x] Conform by the [style guides](https://gitlab.com/gitlab-org/gitlab-ce/blob/master/CONTRIBUTING.md#style-guides)
- [x] Branch has no merge conflicts with `master` (if it does - rebase it please)
- [x] [Squashed related commits together](https://git-scm.com/book/en/Git-Tools-Rewriting-History#Squashing-Commits)

## What are the relevant issue numbers?

https://gitlab.com/gitlab-org/gitlab-ce/issues/13823

See merge request !6818

Fix gitlab:elastic:index_wiki

Closes #1244

See merge request !868

21778 Correct css styles for pinned navigation

## What does this MR do?
Fixes css for header and comment notes when sidebar is pinned

## Screenshots (if relevant)
Before:
![Screen_Shot_2016-11-08_at_11.02.55_AM](/uploads/ae7bb1f477b2ffbd4d4e0364f2770816/Screen_Shot_2016-11-08_at_11.02.55_AM.png)
After:
![Screen_Shot_2016-11-08_at_11.02.34_AM](/uploads/cf0b9f9f175aa5c6c7e79640b76b1040/Screen_Shot_2016-11-08_at_11.02.34_AM.png)

Before:
![Screen_Shot_2016-11-08_at_11.03.21_AM](/uploads/f48ea742ee6dbb86874e47dd27eddadd/Screen_Shot_2016-11-08_at_11.03.21_AM.png)
After:
![Screen_Shot_2016-11-08_at_11.02.19_AM](/uploads/312b27ba07e04ceb96f8ed9d6f167bee/Screen_Shot_2016-11-08_at_11.02.19_AM.png)
## Does this MR meet the acceptance criteria?

- [ ] [Changelog entry](https://docs.gitlab.com/ce/development/changelog.html) added
- [ ] [Documentation created/updated](https://gitlab.com/gitlab-org/gitlab-ce/blob/master/doc/development/doc_styleguide.md)
- [ ] API support added
- Tests
  - [ ] Added for this feature/bug
  - [ ] All builds are passing
- [ ] Conform by the [merge request performance guides](http://docs.gitlab.com/ce/development/merge_request_performance_guidelines.html)
- [ ] Conform by the [style guides](https://gitlab.com/gitlab-org/gitlab-ce/blob/master/CONTRIBUTING.md#style-guides)
- [ ] Branch has no merge conflicts with `master` (if it does - rebase it please)
- [ ] [Squashed related commits together](https://git-scm.com/book/en/Git-Tools-Rewriting-History#Squashing-Commits)

## What are the relevant issue numbers?
Closes #21778 

cc @mikegreiling

See merge request !7362

Give search-input correct padding-right value

## What does this MR do?
This fixes how `padding-right: 20px` was being applied to the style rule of `.search-input`, preventing text in that form from clipping through `.search-icon`

## Are there points in the code the reviewer needs to double check?
If there are any cases where `.search .search-input` is used in a search form where there is no right-side icon (I could not find such occurrence myself).

## Why was this MR needed?
Some text in long search queries were being hidden by the close icon being used in the search form. This makes it a bit more presentable. ;)

## Screenshots (if relevant)
__Before__
![before](/uploads/2757a6264a1d2053af7212f72df7c3f9/before.png)

__After__
![after](/uploads/322fbfa08594f0f33d10a3226c82326d/after.png)

See merge request !7407