Merge patch changelog back into master

/cc @dzaporozhets

Compare api

Fixes #1165

Review changelog

@dzaporozhets updates the changelog and notifies the team.

Improve merge request page UX

Increase Discussions and Changes tabs size. Added count of changes and comment to it

Before and after:

![Screenshot 2014-05-27 12.08.42](https://dev.gitlab.org/uploads/dzaporozhets/gitlabhq/31fe70c9be/Screenshot_2014-05-27_12.08.42.png)

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>

No link inside code block

Improve rake test

Check for `system` call return value instead of `$?.exitstatus`

CSS truncation

Use css truncation for event titles on dashboard. Fix vertical align of timestamps

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

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

Push release doc

Fix drag and drop image tests

Email hint

After this is merged decline http://feedback.gitlab.com/forums/176466-general/suggestions/5767472-move-actionmailer-sending-method-and-smpt-settings

Test ee

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

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

Regression issue

We want to aid communication between the issue tracker team and the release manager with this.

A first example of this issue is https://gitlab.com/gitlab-org/gitlab-ce/issues/294

Add pkgrio to readme

Now that we have instructions on [pkgr.io](https://gitlab.com/gitlab-org/gitlab-recipes/blob/master/install/pkgr/README.md) let's add it to the Readme.