Apply syntax highlighting to fenced code blocks client-side

Instead of applying the syntax highlighting scheme class to these blocks
server-side, we use Javascript and Gon to apply the user's color scheme
(or the default) client-side.

This will make it easier to cache these blocks in the future because
they're no longer state-dependent.

See merge request !1203

UI improvements

* use shared partials for repeating rendering of projects, groups, snippets etc
* more consistency in way how projects, snippets and groups lists are rendered
* fix 500 error when submit project snippet without body
* remove some old and unused css
* more compact search page

See merge request !1214

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>

Prevents an unstyled flash that occurs when we were only applying the
syntax highlighting class in Javascript. Now for these uncached blobs
the server can add the syntax class, and for (possibly) cached fenced
code blocks, the Javascript will add it as needed.

Update PreferencesHelper specs

Update mail_room

See merge request !1213

Enable SSL verification for Webhooks

https://dev.gitlab.org/gitlab/gitlabhq/issues/2121

See merge request !1135

Update CHANGELOG for released 7.14.1

[ci skip]

See merge request !1211

Prevent too many redirects error when home page URL set to external_urll

Many users naively set the home page URL setting to external_url
(e.g. https://mydomain.com). When an unauthenticated user signs in, this
causes endless redirections. For example, this is occuring:

1. Unauthenticated user attempts to access https://mydomain.com/dashboard
2. Application redirects to the home page URL: https://mydomain.com
3. Repeat step 2

In step 3, ApplicationController should have redirected the user to
https://mydomain.com/users/sign_in. Disabling the redirection if home
page URL is the same as external_url prevents users from messing up.

* Closes https://github.com/gitlabhq/gitlabhq/issues/8843
* Closes #2057

See merge request !1210

Limit content width for big screens except certain pages

- [x] limit content width to 1200px
- [x] align header with head
- [x] set full-width for split diff pages

Fixes #2353
Signed-off-by: Dmitriy Zaporozhets <dmitriy.zaporozhets@gmail.com>

See merge request !1207

[ci skip]

Many users naively set the home page URL setting to external_url
(e.g. https://mydomain.com). When an unauthenticated user signs in, this
causes endless redirections. For example, this is occuring:

1. Unauthenticated user attempts to access https://mydomain.com/dashboard
2. Application redirects to the home page URL: https://mydomain.com
3. Repeat step 2

In step 3, ApplicationController should have redirected the user to
https://mydomain.com/users/sign_in. Disabling the redirection if home
page URL is the same as external_url prevents users from messing up.

Closes https://github.com/gitlabhq/gitlabhq/issues/8843
Closes #2057

Improve perofrmance of git blame

https://gitlab.com/gitlab-org/gitlab-ce/issues/2286

Now, it's four times as faster.

See merge request !1209

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

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

Fixed text about HTTP

Fixed for text to be more clear. Because of tweet https://twitter.com/mystygage/status/630798770012323840

See merge request !1921

Change plots to bar graphs

Since line plot does not make sense for this kind of plots, change them to bar graphs. Bar graphs are easier to read and they look cool too.

I would like to change commits per author plots to bar graphs too, but code looks too messy to modify.

See merge request !645

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

Ui improvements

* Improve project name/description look on project page
* Increase width of sidebar for several pages

See merge request !1206

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

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