Fix Social Account Block

If you have omniauth enabled, but don't have one of the "Social" providers enabled (GitHub, Twitter, Google), the "Social Accounts" sections shows up, but without icons. This occurred when I was testing Shibboleth. This fixes the issues by checking if there are any `enabled_oauth_providers` rather than if just `Gitlab.config.omniauth.enabled`. Not quite sure how to implement a test for this, but it works :).

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>

Streamline the content of notification emails

In notification emails, the actual content of the email is often buried under several blocks of chrome — and may even be truncated or completely missing. Ideally, the notification emails would be like *real emails*: a short message of meaningful text, sent from the author of the change that triggered the notification.

This MR includes the following changes to notification emails:

* Remove much of the chrome (e.g. the "GitLab" header)
* Emphasize the content (no more small, grayed-out content)
* Add missing informations to the emails (issue description in "new issue" email, file name in "diff comment" email)
* Add a consistent "View in GitLab" link in the footer
* The assignee is displayed only if someone is assigned
* Fix a rendering bug when viewing emails with [Zimbra](http://www.zimbra.com/)

We use these patches at [Capitaine Train](http://www.capitainetrain.com), and it has been a surprisingly big productivity boost for us.

![Before and after](http://f.cl.ly/items/3n0P2c2v1P0y011c0D3e/Before%20and%20After.png)

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

LDAP code from EE

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

Allow underscore as the first char for project names.

[6.6] Fixes a bug with group member administration

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

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

Group owners were not able to remove any users from their group if they were the only owner.

Catch missing commands in Rake tasks

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

Remove Dot Org

Add envrc to git-ignore

Respect custom gitlab_shell path in gitlab:gitlab_shell:check task

Natural version sorting

Add Enterprise Linux

Increase Nginx Push Size

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 now-invalid invocation of `run_and_match` in gitlab:check

Fix grammar in zero_authorized_projects view

Must have been left over from a previous revision, but the argument
wasn't used anywhere in the method.