Fix broken Wiki Page History

This MR fixes the broken Page History on the Wiki pages. It turns out `WikiHelper` did not allow users to view different versions due to its omitting of query string parameters, which was necessary to specify different `version_id` parameters. Instead of this hacky approach, use manually-specified wildcard routes that match the ID field properly for slashes.

Closes #2104

Closes #1751

Closes #1592

Closes https://github.com/gitlabhq/gitlabhq/issues/9399

See merge request !1232

Remove style attribute from textarea during ZenMode activation

Closes internal https://dev.gitlab.org/gitlab/gitlabhq/issues/2466

Closes https://github.com/gitlabhq/gitlabhq/issues/8963

See merge request !1248

Add syntax highlight scheme to notes rendered client-side

See merge request !1249

Upgrade Redis requirement check to 2.4.0 per https://github.com/mperham/sidekiq/pull/957

Closes #2222

Closes #2445

See merge request !1251

Use File.join to prevent extra slash in help message from appearing. Before:

```
Try fixing it:
sudo -u git -H /opt/gitlab/embedded/service/gitlab-shell//bin/create-hooks
```

See merge request !1252

```
Try fixing it:
sudo -u git -H /opt/gitlab/embedded/service/gitlab-shell//bin/create-hooks
```

Closes #2222

Closes #2445

Closes internal https://dev.gitlab.org/gitlab/gitlabhq/issues/2466

Style project home page

Also make header more compact

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

See merge request !1246

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

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

Add image content-type header in raw download

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

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

See merge request !1245

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>

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>

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>

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>

Fix `rake services:doc` generation

From: https://github.com/gitlabhq/gitlabhq/pull/9604#issuecomment-137539926

See merge request !1243

Add Content-Type header to fix a bug which IE can't show image in
markdown when the image is from raw.

	modified:   CHANGELOG
	modified:   app/controllers/projects/raw_controller.rb
	modified:   spec/controllers/projects/raw_controller_spec.rb

[ci skip]

Ui improvements

* show page context title instead of `Dashboard` keyword
* fix event feed overflow
* remove annoying tooltips where its not needed
* fix tests broken in previous mr

See merge request !1242

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>

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>

Collection of fixes and improvements to GitLab UI

* new design colors
* new font size
* change padding and size of form inputs
* new activity page
* new groups page
* new explore projects page
Signed-off-by: Dmitriy Zaporozhets <dmitriy.zaporozhets@gmail.com>

cc @skyruler

See merge request !1239