rebased with latest changes from master

Rebased to resolve merge conflicts

Requested in #14669

Added note to changelog

PipelinesFinder use git cached data

See merge request !4984

Fixes missing avatar on system notes

Closes #17295


![Screen_Shot_2016-06-27_at_12.50.50_PM](/uploads/b142226e608ccfe751a9b6059f57c9ec/Screen_Shot_2016-06-27_at_12.50.50_PM.jpg)

See merge request !4954

Markdown toolbar inserts code blocks

## What does this MR do?

Adds the ability to insert code blocks with the markdown toolbar buttons. This is done by selecting the block & then clicking the code button.

## What are the relevant issue numbers?

Closes #19173 


See merge request !4950

Fixed avatar alignment in new MR view

## What does this MR do?

Fixes the alignment of the avatar in new MR view.
Closes #19076 

## Screenshots (if relevant)

![Screen_Shot_2016-06-24_at_12.53.58](/uploads/fc94faf2e48f194852693b7ae79e8fa3/Screen_Shot_2016-06-24_at_12.53.58.png)

See merge request !4901

Workhorse to serve email diffs

See merge request !4590

Show basic system info on admin panel. Closes #18886

![Screen_Shot_2016-06-23_at_10.57.07_AM](/uploads/df33bc3dc36ceaf86f5e479ca15b83f3/Screen_Shot_2016-06-23_at_10.57.07_AM.png)

See merge request !4858

Fix group visibility form layout in application settings

## What does this MR do?

This fixes UI consistency related to setting group visibility levels in application settings. See screenshots.

## Screenshots (if relevant)

#### Before

![visiblity_consistency](/uploads/9cf9b517e25cd661ac61bdd7ca2d82f4/visiblity_consistency.png)

#### After

![group_visibility_after](/uploads/7b317684d047716f2aa5e60d19a4281b/group_visibility_after.png)

See merge request !4848

Closes #18949

Fixed dropdown not filtering queries entered before data is loaded

## What does this MR do?

Triggers a 'keyup' event on a filters input to force it to process any text that was added before the data was retrieved and rendered.

## Are there points in the code the reviewer needs to double check?

😕 

## Why was this MR needed?

UX

## What are the relevant issue numbers?

Closes #18942.

## Screenshots (if relevant)

## Does this MR meet the acceptance criteria?

- [ ] [CHANGELOG](https://gitlab.com/gitlab-org/gitlab-ce/blob/master/CHANGELOG) entry added
- [ ] [Documentation created/updated](https://gitlab.com/gitlab-org/gitlab-ce/blob/master/doc/development/doc_styleguide.md)
- [ ] API support added
- Tests
  - [ ] Added for this feature/bug
  - [ ] All builds are passing
- [x] Conform by the [style guides](https://gitlab.com/gitlab-org/gitlab-ce/blob/master/CONTRIBUTING.md#style-guides)
- [x] Branch has no merge conflicts with `master` (if you do - rebase it please)
- [x] [Squashed related commits together](https://git-scm.com/book/en/Git-Tools-Rewriting-History#Squashing-Commits)

See merge request !4846

[ci skip]

Fix CHANGELOG

Fixes double header for 8.9.3 entries

See merge request !4971

Find all builds for commit if there are multiple pipelines for it

## What does this MR do?

This MR fixes a builds API. When multiple pipelines were triggered for a commit, then API returned builds only from the last pipeline.

## What are the relevant issue numbers?

Closes #18912  
Closes #19243 

## Does this MR meet the acceptance criteria?

- [x] [CHANGELOG](https://gitlab.com/gitlab-org/gitlab-ce/blob/master/CHANGELOG) entry added
- [x] [Documentation created/updated](https://gitlab.com/gitlab-org/gitlab-ce/blob/master/doc/development/doc_styleguide.md)
- [x] API support added
- Tests
  - [x] Added for this feature/bug
  - [x] All builds are passing
- [x] Conform by the [style guides](https://gitlab.com/gitlab-org/gitlab-ce/blob/master/CONTRIBUTING.md#style-guides)
- [x] Branch has no merge conflicts with `master` (if you do - rebase it please)
- [x] [Squashed related commits together](https://git-scm.com/book/en/Git-Tools-Rewriting-History#Squashing-Commits)

See merge request !4849

Use clock_gettime for all performance timestamps

This MR adjusts the performance monitoring code to use `Process.clock_gettime` (thus `clock_gettime(3)`) instead of `Time.now`.

Using `Time.now` / `Time.new` adds more overhead than `Process.clock_gettime`, it also doesn't provide a way of getting timestamps in nanoseconds (which `Process.clock_gettime` does allow).

See merge request !4899

Implement UI for new project page

## What does this MR do?

Updates the project creation page to conform with the latest UI updates.

## Are there points in the code the reviewer needs to double check?

Ney.

## Why was this MR needed?

Updated UI.

## What are the relevant issue numbers?

Closes #2542.

## Screenshots (if relevant)

**Desktop:**

![Screen_Shot_2016-06-18_at_04.00.48](/uploads/0313eee96a2aef9ed5e048989548b133/Screen_Shot_2016-06-18_at_04.00.48.png)

**Mobile:**

![Screen_Shot_2016-06-18_at_04.01.00](/uploads/505b110c3fcbf523aac08797db9f6781/Screen_Shot_2016-06-18_at_04.01.00.png)

See merge request !4766

Process.clock_gettime allows getting the real time in nanoseconds as
well as allowing one to get a monotonic timestamp. This offers greater
accuracy without the overhead of having to allocate a Time instance. In
general using Time.now/Time.new is about 2x slower than using
Process.clock_gettime(). For example:

    require 'benchmark/ips'

    Benchmark.ips do |bench|
      bench.report 'Time.now' do
        Time.now.to_f
      end

      bench.report 'clock_gettime' do
        Process.clock_gettime(Process::CLOCK_MONOTONIC, :millisecond)
      end

      bench.compare!
    end

Running this benchmark gives:

    Calculating -------------------------------------
                Time.now   108.052k i/100ms
           clock_gettime   125.984k i/100ms
    -------------------------------------------------
                Time.now      2.343M (± 7.1%) i/s -     11.670M
           clock_gettime      4.979M (± 0.8%) i/s -     24.945M

    Comparison:
           clock_gettime:  4979393.8 i/s
                Time.now:  2342986.8 i/s - 2.13x slower

Another benefit of using Process.clock_gettime() is that we can simplify
the code a bit since it can give timestamps in nanoseconds out of the
box.

Unused gon variable with very bad performance

## What does this MR do?

Remove an unused variable with a lot of performance penalty. It was opening a transaction just to return a constant string.

## Does this MR meet the acceptance criteria?

- [x] [CHANGELOG](https://gitlab.com/gitlab-org/gitlab-ce/blob/master/CHANGELOG) entry added

See merge request !4969

In any case if just want the value which is always ‘gitlab’

require 'benchmark/ips'

Project.first # To load database things
GitlabIssueTrackerService.first # To load database things

Benchmark.ips do |x|
  x.config(:time => 5, :warmup => 2)

  x.report("current") do
    Project.new.default_issue_tracker.to_param
  end

  x.report("") do
    'gitlab'
  end

  x.compare!
end

Calculating -------------------------------------
             current     4.000  i/100ms
                        30.938k i/100ms
-------------------------------------------------
             current     47.298  (±10.6%) i/s -    232.000 
                          4.366M (±20.9%) i/s -     17.202M

Comparison:
                    :  4366456.0 i/s
             current:       47.3 i/s - 92318.26x slower

docs: fix default_branch_protection default



See merge request !4479

Switched mobile button icons to ellipsis and angle

## What does this MR do?
Switches the mobile button icons

## What are the relevant issue numbers?
Closes #19170   
Part of #19200 

## Screenshots (if relevant)
![Screen_Shot_2016-06-27_at_9.08.28_AM](/uploads/7784489402e342e671d02b24d2ea0d64/Screen_Shot_2016-06-27_at_9.08.28_AM.png)


See merge request !4944

Resolve "Pin should show up at 1280px min"

## What does this MR do?
Decreased window min width for pinned sidebar

## What are the relevant issue numbers?
Closes  #19171    
Part of #19200 

## Screenshots (if relevant)
![Screen_Shot_2016-06-27_at_9.36.13_AM](/uploads/d0a87bca5af1bee808c5b1046c0ecf72/Screen_Shot_2016-06-27_at_9.36.13_AM.png)

See merge request !4947