Reorder MergeRequestTabs constructor

The tab was being activated before we set the `[commits|diffs]Loaded`
variable, so even when the `/diffs` route is accessed directly, like
from the "Side-by-side" link, the tab was being loaded from its default
source.

Fixes #1887

See merge request !892

Update permissions for issue tracker management

Don't allow guest or reporter to set assignee, milestone and label when create or update new issue and merge request.
After this change `Guest` and `Reporter` rule is used to report issues but only `Developer` and higher roles can manage issues (schedule milestone, assign to user or close any issue)

Also I removed some duplication code between issues and merge requests and put all issuable partials in one directory

See merge request !890

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>

added info about GitHub importing

Added info that importing doc also works for GitHub EE.

https://dev.gitlab.org/gitlab/gitlabhq/issues/2410#note_49396

See merge request !1878

Add SAML to list of social_provider

Resolves issue 1888.  Still an issue because the SAML link under Connected Accounts will not have a logo.

See merge request !891

The tab was being activated before we set the `[commits|diffs]Loaded`
variable, so even when the `/diffs` route is accessed directly, like
from the "Side-by-side" link, the tab was being loaded from its default
source.

Fixes #1887

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>

Have sidebar labels disappear behind content instead of hide immediately when collapsing.

I'm not sure how to make a gif out of it, but I promise it looks pretty :)

See merge request !888

prettier highlighting of active link in the sidebar

Before:

![Screenshot_2015-06-25_11.17.08](https://dev.gitlab.org/gitlab/gitlabhq/uploads/851606a122c1d1174d0f97857ad472d3/Screenshot_2015-06-25_11.17.08.png)

After:

![Screenshot_2015-06-25_11.17.42](https://dev.gitlab.org/gitlab/gitlabhq/uploads/b8dc55bcd76dac29652ef5d25f99ccff/Screenshot_2015-06-25_11.17.42.png)

Only with this theme it's not an improvement (this is an honest merge request (trademark pending)) :

![Screenshot_2015-06-25_11.18.35](https://dev.gitlab.org/gitlab/gitlabhq/uploads/5d631a11ee866f5fc51e985b02a836ba/Screenshot_2015-06-25_11.18.35.png)

See merge request !1879

Show a random Markdown tip in the textarea placeholder

cc @darby

See merge request !879

Removed the icons from the New Issue and New Project buttons

Fixes #1869

No more icons!

See merge request !885

Change the default admin password

Closes internal https://dev.gitlab.org/gitlab/gitlabhq/issues/2422

See merge request !865

Performance improvements

* store @participants in variable
* store result of subscribed? call into variable

In total it reduce amount of SQL queries for issue or merge_request with 10 comments/participants almost twice.

See merge request !883

Add 2FA status to user admin API

This MR adds the `two_factor_enabled` field to the admin's API to indicate whether a given user has enabled 2FA.

See merge request !881

Updated merge request merged web hook to correctly fire action=merged.

I believe this merge request will fix both issues #879 and #498.

If a merge request was merged via the command line, the correct web hook was fired with the field `object_attributes.action = "merge"`. However, if the merge request was merged via the web UI, the webhook would be fired with `object_attributes.action = "open"`.

See merge request !780