Side nav scrolls if content height taller than screen

## What does this MR do?
Header logo is now fixed at top; put back scrolling functionality in side nav

## Screenshots (if relevant)
<img src="/uploads/e1d1b60c296c39c61d7fe7da22b6c52d/scroll.gif" width="600px">

See merge request !4513

Disable CSRF protection when serving Git HTTP clients

Fixes https://gitlab.com/gitlab-org/gitlab-ce/issues/18331

See merge request !4538

Add new icons in left sidebar and layout nav

Closes #17609    
Closes #17240    
Closes #17321    

![Screen_Shot_2016-06-02_at_8.47.38_AM](/uploads/f254fe81cba65cbdeb8e5720f0b2fc19/Screen_Shot_2016-06-02_at_8.47.38_AM.png)
![Screen_Shot_2016-06-02_at_8.53.33_AM](/uploads/2c27284f0a4916fe447794d9b663c4df/Screen_Shot_2016-06-02_at_8.53.33_AM.png)

@skyruler I couldn't find the icons for `Projects`, `Merge Requests`, `Snippets`, or `Help` in the design repo. Do you have them available somewhere?

See merge request !4268

Use container helper instead of hard coded container

## What does this MR do?
Add `container_class` helper class to fix layout bug

## What are the relevant issue numbers?
#18333 
## Screenshots (if relevant)
Fixed:    
![Screen_Shot_2016-06-08_at_2.03.38_PM](/uploads/6e7575d711efb8eaf6ba641907b2d607/Screen_Shot_2016-06-08_at_2.03.38_PM.png)
Fluid:     
![Screen_Shot_2016-06-08_at_2.03.56_PM](/uploads/33d3f73781ca9ed129f853abfe9feb4b/Screen_Shot_2016-06-08_at_2.03.56_PM.png)

See merge request !4543

Fixed dropdown link line-height

## What does this MR do?

Fixes line-height issue on dropdown menu links

## Why was this MR needed?

The line-height of some dropdown links were taking the parent, most noticeable the commit header

## Screenshots (if relevant)

Before:

![Screen_Shot_2016-06-08_at_12.26.13](/uploads/51d6bbb4d727da0e3f27d715d6556d4f/Screen_Shot_2016-06-08_at_12.26.13.png)

After:

![Screen_Shot_2016-06-08_at_12.25.03](/uploads/2dcbfaa67982500eef42cfe4247cd54d/Screen_Shot_2016-06-08_at_12.25.03.png)

See merge request !4531

Improve ui consistency

* Decline idea of using gray buttons actively in UI
* remove icons from some buttons that already has text
* standardizes margin between buttons 


First step in https://gitlab.com/gitlab-org/gitlab-ce/issues/18324 

See merge request !4533

Allow custom text on 'almost there' page

Add a new application setting, after_sign_up_text. This is text to be
rendered as Markdown and shown on the 'almost there' page after a user
signs up, but before they've confirmed their account.

Closes #14098.

See merge request !4098

Allow clones from /namespace/project

Allow `git clone https://host/namespace/project` to work, in addition to `git clone https://host/namespace/project.git`

Closes #13840.

See merge request !4530

Redirect /namespace/project/info/refs to
/namespace/project.git/info/refs, so `git clone` works on either
namespace/project.git or namespace/project.

Added minimum password length to password field

Add a placeholder to the password field in the register form with the minimum number of characters required. Also added a pattern to the field to stop it submitting if less than that.

Closes #17765

See merge request !4458

Set target="_blank" for external links

Closes #14553

See merge request !4526

Disable Rails/UniqBeforePluck rubocop cop

 Rails/UniqBeforePluck seems to have some bugs 

* https://github.com/bbatsov/rubocop/issues/3122
* https://github.com/bbatsov/rubocop/issues/3148

and we had some problems in EE with that https://gitlab.com/gitlab-org/gitlab-ee/merge_requests/425#note_12245005

See merge request !4477

[ci skip]

Add a new application setting, after_sign_up_text. This is text to be
rendered as Markdown and shown on the 'almost there' page after a user
signs up, but before they've confirmed their account.

Tweak the styles for that page so that centered lists look reasonable.

Sidebar updates

## What does this MR do?
Updates `nav/_admin.html.haml` and `nav/_explore.html.haml` to match new compact sidebar design

## Screenshots (if relevant)
![Screen_Shot_2016-06-07_at_2.19.18_PM](/uploads/5699987001de901a67d503b097d1b19d/Screen_Shot_2016-06-07_at_2.19.18_PM.png)

See merge request !4517

Update Knapsack report only on master

## What does this MR do?

Makes to generate Knapsack report only on master. This speed-ups tests, because the last stage can be run significant time after previous stages.


See merge request !4540

Optimize issuable APIs interaction with notes

See merge request !4471

Remove notification settings in batches

## What does this MR do?

This improves the performance of the migration `db/migrate/20160603180330_remove_duplicated_notification_settings.rb` by removing duplicate rows in batches instead of using a single big `DELETE FROM` query.

## Why was this MR needed?

The original migration would locally take 45 minutes to complete, possibly up to hours on GitLab.com and similar setups.

## What are the relevant issue numbers?

#18289

See merge request !4529

Removable labels from filtered issuables label bar

When filtering by labels, a remove button appears next to each label. This then removes that label & refreshes the issuable filter form

![Screen_Shot_2016-05-17_at_12.07.47](/uploads/b21e86247aa1bbfd347bef1eb21f1562/Screen_Shot_2016-05-17_at_12.07.47.png)

Closes #15474

See merge request !4178

Backported from EE shared form for web hooks

## What does this MR do?

EE uses a shared form for web hooks - so this brings that across to CE.

See merge request !4457

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

This was not a clear cut n+1 query, given that if you're directly subscribed to all issues
that the API is returning you never really need to check for the notes. However, if you're
subscribed to _all_ of them, then for each issuable you need to go once to `notes`, and
once to `users` (for the authors). By preemtively loading notes and authors, at worst you have
1 extra query, and at best you saved 2n extra queries. We also took advantage of this preloading
of notes when counting user notes.

`notes_with_associations` are used for `participant` declarations, but `Participable`
only really cares about the target entity project, and not the participants
projects.

`notes_with_associations` are also used in `Commit::has_been_reverted?` which
employs the reference extractor of the commit, so no references to the notes
projects are made there (`Mentionable::all_references` cares only about the
`author` and other `attr_mentionable`). A paralel situation occurs on
`Issue::referenced_merge_requests`.

This improves performance of the duplicate notification settings
migration by removing duplicates in batches instead of using one big
"DELETE FROM" query.

The previous query would locally run over 45 minutes without even
finishing. This new setup finished in a matter of seconds.

Fixes #18289

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

Add fog-azure to supported backup list

!4396 left out Azure by accident.


See merge request !4444

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