Prevent double-prefixing of help page paths

Closes #2679 

See merge request !1400

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Show CI status for each commit row on pages like: Commits, Merge request (commits tab), Compare etc

![Screenshot_2015-09-23_12.34.50](https://gitlab.com/gitlab-org/gitlab-ce/uploads/d40d6a69f76128e32d3a0cb641b3495b/Screenshot_2015-09-23_12.34.50.png)


Fixes #2632 

See merge request !1402

Correct markdown.md docs RE use in commit messages.

This is an improvement to the situation covered in issue #1582. It corrects the markdown documentation to demonstrate that GFM cannot currently be used in commit messages.

See merge request !1343

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 error when MR source branch no longer exists.



See merge request !1393

Fix user identities API

Added ability to update or set the identity of an existing user, like the documentation said it was possible, but actually wasn't.

@DouweM or @stanhu could you please take a look at my code, and see if its sound?

/cc @JobV 

See merge request !1398

Prior, because the link "api/README.md" was matched twice, the first
link became "help/help/api/README.md". Now we do a negative lookahead to
make sure the link doesn't start with `help/`.

This fix is still not ideal, see TODO note.

Added ability to update or set the identity of an existing user, like the documentation said it was possible, but actually wasn't.

Clarify confirmation text on user deletion.

See #1699

Some users thought it was ok to delete the user because they'd only use the issues.  
This clarifies a bit better what's being deleted when you delete a user.

See merge request !1382

Fix CI backup step in migration guide

[ci skip]

See merge request !1397

[ci skip]

Skip check_initd_configured_correctly on omnibus installs

This was causing the task `gitlab-rake gitlab:incoming_email:check`
to fail.

See merge request !1396

Add better deprecation notice for the upgrader. Too easy to miss otherwise https://twitter.com/0x663030623472/status/646262552796594176

This was causing the task `gitlab-rake gitlab:incoming_email:check`
to fail.

8.0.0 is released; add 8.0.1 entry to CHANGELOG

[ci skip]

See merge request !1394

[ci skip]

Update CHANGELOG

Add to migration on what to do if you don't want your data.

If you don't want to migrate your CI data , remove the old builds directory.

See merge request !1392

Mention Reply by email in installation doc.

Added the "Enable Reply by email" section and moved the others around.

See merge request !1390

Ci migration doc improvements

Use export improvements in CI 8.0.1, make upgrades a more prominent part of the process, do not shut down GitLab during CI data import.

See merge request !1387

8.0.0 has been released