Cleaner headers in Notification Emails

Make the informations available in the notification email headers (sender, recipient, subject, etc.) more readable and meaningful.

* Remove the email subject prefix
* Don't write the project namespace in email subjects
* Write the issue/merge request title in the notification email subject
* Make the email appear as sent from the action author (the actual email address is still `gitlab@gitlab.com`)

For instance, this is the notification email for a new issue comment before:

> From: gitlab@gitlab.com
> To: myemailaddress@gmail.com
> Subject: GitLab | GitLab HQ / GitLab-Shell | New note for issue #1234

And after :

> From: Nick Brown <gitlab@gitlab.com>
> To: myemailaddress@gmail.com
> Subject: GitLab-Shell |  Add local update hook  (#1234)

The recipient of the notification can easily get the gist of the message without even opening it — just by looking at how it appears in her inbox. None of the actual email addresses (From, To, Reply-to) changes, just the display name.

Having a consistent subject for all notification emails sent about some resource also allow good email clients to group the discussion by thread (although grouping in Mail.app still needs some work).

Main purpose is move big amount of methods from user, group, project
models and place filtering logic in one place.
It also fixes 500 error on group page for PostgreSQL
Signed-off-by: Dmitriy Zaporozhets <dmitriy.zaporozhets@gmail.com>

Blob and tree gfm links to anchors work.

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>

Public Groups

This is the initial work (meaning no tests) for making groups public if they have a public project (or internal for logged in users). This allows issues and merge requests to be viewed, but _not_ group membership. As part of this I have also added back the link in the public project title section (it was removed as it didn't make sense before).

This addesses the following suggestions/issues:

http://feedback.gitlab.com/forums/176466-general/suggestions/5314461-groups-containing-one-or-more-public-projects-shou
Issue #32
https://github.com/gitlabhq/gitlabhq/issues/5203
as well as a few closed issues.

This also changes the public user page to only show groups that are accessible to the user in some manner.

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

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

Add jasmine tests to postgresql db

Also fixes issue with branch/tag removing via UI
Signed-off-by: Dmitriy Zaporozhets <dmitriy.zaporozhets@gmail.com>

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

Better css class names for diff elements

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>

Because .content class used in several other places and this change add
unnecessary margint ot it

This reverts commit f8807281.

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

Refactor Css

Fixes #6046

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

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

Conflicts:
	CHANGELOG

Styleguide

As discussed.

postgresql testing on travis

set layout margin-bottom 50px

Add support for Gemnasium as a project service

Conflicts:

	db/schema.rb

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

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

Conflicts:
	CONTRIBUTING.md