Use ENV variables for Unicorn worker killer & increase default limits

Merge request that lead to this particular merge request:
https://gitlab.com/gitlab-org/gitlab-ce/merge_requests/2421

[ci skip]

See merge request !2513

Upgraded gitlab_git to fix issue #5858

This updates the dependency on gitlab_git and fixes #5858 - reproduced locally and issue disappears with the change.

Related MR that actually adds branch name support to commits_between: https://gitlab.com/gitlab-org/gitlab_git/merge_requests/61

See merge request !2516

Fixes tooltip doesn't duplicate the "me" name.

Checks that "me" is not in the array of names in tooltip

![emojilist](/uploads/20b1a39cda194358f9730ec3c6b86acb/emojilist.gif)

Closes https://gitlab.com/gitlab-org/gitlab-ce/issues/7978


See merge request !2454

Adds "t" as a shortcut for find file anywhere



See merge request !2507

Fixed invalid JSON in first JSON Example

Just a comma missing

See merge request !2487

Update Issues/MRs updated_at field when notes are generated

Closes #3749 and #9130

See merge request !2493

Remove `Compressed to` column from build artifacts browser

See #10982.

See merge request !2509

Using this limit on GitLab.com it appears we're able to reduce response
timings by about 620 milliseconds compared to the previous limit.

See gitlab-org/gitlab-ce!2421 for more information.

This makes it easier for users to use their own limits based on their
server configuration.

[ci skip] Fixed minor typo in workflow documentation

This change is self-explanatory.

See merge request !2503

See #10982.

Code was failing because branch was named `'test'` with quotes
which was escaping the javascript I was using.

Also adds autocomplete="off" to find input.

- Add attribution for Anton Baklanov
- Remove attributions for employees

[ci skip]

Added X-GitLab-... headers to emails from CI and Email On Push services

Fixes #2098

This adds the 'X-GitLab-Project', 'X-GitLab-Project-Id' and
'X-GitLab-Project-Path' headers to emails from CI and Email On Push in a way
that it is done currently for merge requests and issues emails.

Additionally, CI emails will have 'X-GitLab-Build-Status' header with either
'fail' or 'success'.

Emails from Email On Push will include 'X-Gitlab-Author' header containing the
username of user who did the push.

See merge request !2159

sometimes `@ref` will be `nil`.
this makes sure that the correct branch is passed in.

Allow LDAP users to change their email if it was not set by the LDAP
server

Fixes https://gitlab.com/gitlab-org/gitlab-ce/issues/3054

See merge request !2502

Add public params to GET /projects api. Closes #3788



See merge request !2409

Starring project only increases star count

This is instead of increasing star & fork count

Fixes #11396

![star-count](/uploads/9a1d569393bc051d1a019f0340eec957/star-count.gif)

cc. @jschatz1 

See merge request !2504

Fixes #2098

adds exclamation point when assigned user cannot merge

Fixes: #4175 

See merge request !2408

# Conflicts:
#	db/schema.rb

This is instead of increasing star & fork count

Fixed #11396

Creator should be added as a master of the project on creation

Fixes: #4222

See merge request !2463

Greatly improve external_issue_tracker performance

See 3d41133d48f6522b8755bb91b804864e8e520871 for all the details. As an aside, this commit contains a set of migrations that will introduce downtime as they add a column with a default value which in turn locks the entire table (at least on PostgreSQL).

See merge request !2498