Fix Error 500 occuring with repositories that have a bad HEAD

A repository could have objects but no valid HEAD, causing `project.commit` to be `nil`.

See merge request !1433

A repository could have objects but no valid HEAD, causing
`project.commit` to be `nil`.

Hook api updates



See merge request !1429

Get CI token from ci projects

This fixes problem when GitLabCiService had different token than stored
in Ci::Project.

See merge request !1425

Update 7.14-to-8.0.md

Update mailroom to 0.5.2

Fixes #2698 and #2711.

See merge request !1424

Add the newrelic-grape gem

This allows us to see a breakdown of API requests in New Relic.

See merge request !1419

Fix default avatar not showing up in network graph

The change in 71cdb249 removed the `/assets` path in the default avatar to eliminate runtime errors, but this was one place where `image_path` was missed. If the user full URL is specified, `image_path` does nothing.

Closes https://github.com/gitlabhq/gitlabhq/issues/9657

See merge request !1411

Add Troubleshooting section to 8.0 docs

[ci skip]

See merge request !1416

Refer to Apache templates in 8.0 update guide

[ci skip]

See merge request !1426

Closes https://github.com/gitlabhq/gitlabhq/issues/9657

Remove CI dashboard

With CI status integrated at GitLab projects page there is no reason to keep it
anymore.
Signed-off-by: Dmitriy Zaporozhets <dmitriy.zaporozhets@gmail.com>

Part of #2594 

See merge request !1422

With CI status integrated at GitLab projects page there is no reason to keep it
anymore.
Signed-off-by: Dmitriy Zaporozhets <dmitriy.zaporozhets@gmail.com>

Show CI status on Your projects page and Starred projects page
Signed-off-by: Dmitriy Zaporozhets <dmitriy.zaporozhets@gmail.com>

Part of #2594 

Screenshot: 

![Screenshot_2015-09-24_13.42.52](https://gitlab.com/gitlab-org/gitlab-ce/uploads/0516ea02b72457a431bd72d3f6619dfe/Screenshot_2015-09-24_13.42.52.png)


See merge request !1420

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

Use standard Markdown font in Markdown preview instead of fixed-width font

Closes #2585

See merge request !1414

Build status on commit page

Screenshot:

![Screenshot_2015-09-24_11.29.54](https://gitlab.com/gitlab-org/gitlab-ce/uploads/49d1b9dc60d328dceaf771b5e44726ca/Screenshot_2015-09-24_11.29.54.png)

Part of #2594 

See merge request !1418

This allows us to see a breakdown of API requests in New Relic.

Fix Slack notification URL and remove the usage of Ci::RoutesHelper

Fix for #2644

/cc @dzaporozhets @rspeicher 

See merge request !1391

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>

Move CI charts to project graphs area

Part of #2594 

Should be merged after !1405 


Same page but moved to another place 

![Screenshot_2015-09-23_16.25.15](https://gitlab.com/gitlab-org/gitlab-ce/uploads/ef7266de0528bd6dd3f95159e161ea9a/Screenshot_2015-09-23_16.25.15.png)


See merge request !1407

Made some steps to add SSH keys more clear



See merge request !1936