Github importer: AJAX update status

#1907

See merge request !1417

Add action property to merge request hook

Github importer feature desc

@job Can you take a look?

See merge request !1414

Border radius fixx

Fixes the border radius in the description box.

See merge request !1416

print validation errors when gitlab-rake gitlab:import:repos fails for project

Currently, when gitlab-rake gitlab:import:repos is not able to import a project it justs prints "Failed trying to create project" to the console. There seems to be no way to find out what exactly has failed. Since the check uses validation, it should at least print the validation issues. That might be a bit cryptic, but may be better than leaving the user in the dark completely.

See merge request !147

Fix the email variable substituation in ssh help page

Update doc github importer.

See merge request !1413

Update doc github importer

See merge request !1412

Update oauth documentation

See merge request !1411

Spinach admin application

See merge request !1410

Check for database connection when running current_application_settings

The PG connection errors don't always end up being caught as ActiveRecord::NoDatabaseError. So when doing a precompile without the database (like when using the omnibus), an exception was being thrown.

See merge request !292

Use full path from root of project.

Remove markdown syntax from config file

Add placeholder values to hipchat service

This MR adds placeholder values to the hipchat service.
This should prevent issues like #279 or #772 that popped up because people didn't know what exactly they are supposed to enter in the fields.

See merge request !294

Add syntax colors to diffs in email-on-push notifications

## What does this MR do?
This MR adds syntaxhighlighting to the email-on-push notifications.
## Are there points in the code the reviewer needs to double check?
No
## Why was this MR needed?
Currently the diff in email-on-push notifications is just a monochrome diff that's hard to read.
This MR adds colored syntaxhighlighting to the mails.
## What are the relevant issue numbers / Feature requests?
* It closes https://github.com/gitlabhq/gitlabhq/issues/6994
* There is a Discussion in the Feedback Forum: http://feedback.gitlab.com/forums/176466-general/suggestions/5802256-add-color-to-diffs-in-email-on-push-service-to-htm
* A pull request for this already existed, but was closed. https://github.com/gitlabhq/gitlabhq/pull/7739

## Screenshots
see prior Pull Request for a screenshot

See merge request !295