Teach GitLab not only to merge changes from a merge-request, but also to
apply patches posted to merge-request in a way like `git am` would do -
without merge commit and directly on top of current branch. Which way to
go is selected by user in web UI, and apply patches is the first option.

There are 3 cases:

- only 1 commit is present in MR -> the only available option is to
  apply that single commit as one patch without a merge

  ( There is no need for merge commit in this case at all: information
    about user who applied the patch goes to "Committer" field in resultant
    commit. Avoiding 1 merge per 1 patch results in cleaner history )

  It is also possible to review patch description directly in web UI,
  before doing the actual application, and correct / amend it as needed.

- several commits are present in MR:

  * it is possible to apply the patches directly on top of current
    branch. Again information about who applied what goes to "Committer"
    field.

  * it is possible to merge MR changes with making a merge commit.

    This variant is useful, when patches from a MR do several logical
    steps to reach one goal, and MR description contain cover letter for
    whole patch series.

    in this case original commits stay untouched and resulting merge
    will contain MR author as author, user who accepted MR as committer,
    and cover letter as merge commit message.

    NOTE we avoid useless "Merge branch X into Y" in merge message, and
        just put MR title into merge subject and MR description into merge
        description.

        This way it is more logical with more important information in
        merge subject and thus e.g. more handy to oversee what a merge brings,
        just by it subject, e.g. via looking at updates via

            gitk --first-parent ...

        or via web.

NOTE for pre-generated references to merge-request we now use full MR
    URL, instead of !<MR-n>. Full URLs work everywhere, not only on
    original site where MR was created, or even only in original repo
    and not its fork on the same site.

* origin/8-5-stable:
  Remove "(unreleased)" from 8.5.4 release notes
  Merge branch 'fix/invalidate-builds-badge-cache' into 'master'
  Version 8.5.3
  Merge branch 'renaming-repository-caching' into 'master'

[ci skip]

Invalidate cache for builds badge

This fixes cache issue with badges (we should not cache badge images).

Closes #13982

See merge request !3086

Flush repository caches before renaming projects

This should hopefully solve gitlab-org/gitlab-ce#13790. Once I know the exact steps to reproduce the problem I should be able to confirm this.

cc @dblessing @inem

See merge request !2974

* 8-5-stable:
  Version 8.5.2
  Merge branch 'docs_todos' into 'master'
  Merge branch 'fix/13785-dashboard-projects-display-welcome-after-search' into 'master'
  Merge branch 'fix/13781-delete-tag-without-ajax' into 'master'
  Merge branch 'fix/deprecated-ci-badge-permissions' into 'master'
  Merge branch 'issue_13623' into 'master'
  Merge branch 'fix/12652-omniauth-import-from-gitlab-com-fails' into 'master'
  Merge branch 'shortcuts-help' into 'master'
  Merge branch 'rel-url-fix' into 'master'
  Merge branch 'sidebar-overlap-fix' into 'master'
  Merge branch 'rs-improve-grace-period' into 'master'
  Merge branch 'issue_13648' into 'master'
  Merge branch 'issue_13621' into 'master'
  Merge branch 'issue_13851' into 'master'
  Merge branch 'fix-migration' into 'master'
  Merge branch '11489-branded-appearance-to-ce' into 'master'
  Update Rails to 4.2.5.2

Add Todos documentation

Closes https://gitlab.com/gitlab-org/gitlab-ce/issues/13884

See merge request !3064

Don't show "Welcome to GitLab" when the search didn't return any projects

Fixes #13785. /cc @pixdrift

### Before

![Screen_Shot_2016-03-02_at_10.55.02](/uploads/b6b6ead2143d01e374ad296e72182d79/Screen_Shot_2016-03-02_at_10.55.02.png)

### After

![Screen_Shot_2016-03-02_at_12.12.33](/uploads/6e16c44e69039c534ea0fc3373c6060b/Screen_Shot_2016-03-02_at_12.12.33.png)

See merge request !3059

Tag deletion doesn't use AJAX anymore

See merge request !2986

Fix permissions for deprecated CI build status badge

This fixes permissions for deprecated status badge, being unavailable even if project is public.

Closes #13324

See merge request !3030

Show days remaining instead of elapsed time for Milestone.

Closes #13623

See merge request !2978

Fix import from gitlab.com fails

_Originally opened at !2896 by @kazsw._

- - -

Fixes #12652

CGI.escape encodes '/' by default.
Second argument can be removed.

See merge request !2988

Fix help keyboard shortcut for relative URL setups

Fixes gitlab-org/gitlab-ce#12751

See merge request !3016

Fix relative URL

See https://github.com/gitlabhq/gitlabhq/issues/10053

 1. Same configuration way for relative URL like with Omnibus
 2. Loading the relative configuration from Rakefile as Rails do not load initializers for `asset:precompile`

First point has another positive side effect: no collisions (due to git controlled `application.rb`) any more during the upgrades of source based installations and relative url configuration

 - [x] tests on the source based installation
 - [x] tests on the centos&ubuntu omnibus packages

Fixes: gitlab-org/gitlab-ce#13730, gitlab-org/gitlab-ce#13727, gitlab-org/omnibus-gitlab#1143 and https://github.com/gitlabhq/gitlabhq/issues/10053

See merge request !2979

Fix issue with overlap of sidebar links.

Thanks @iamphill for the help with this one. 

![Screen_Shot_2016-03-01_at_10.19.52_AM](/uploads/f203fde79ae397ad18f23c4108f1c306/Screen_Shot_2016-03-01_at_10.19.52_AM.png)

cc @iamphill @alfredo1 @dzaporozhets @rymai 

See merge request !3043

Don't show any "2FA required" message if it's not actually required

Prior, if the user had enabled and then disabled 2FA, they would be
shown a "You must enable Two-factor Authentication for your account."
message when going back to re-activate it, even if 2FA enforcement was
disabled.

See merge request !3014

Improve implementation to check read access to forks and add pagination.

Fixes #13648

The following optimizations where made:

- Pagination was added.
- Code to check for read permissions to forks was optimized, in the past we were doing too many queries for each project.

See merge request !2991

Don't repeat labels listed on Labels tab.

Fixes #13622

See merge request !2924

Brings back missing "Gitlab" text on the logo

Closes #13851 

See merge request !2989

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

For !2927 

See merge request !3011

Branded appearance to CE

Closes #11489

The difference with the EE version is only that there is no distinction between light and dark logos, though this wasn't used anyway. If this is fine, I'll create a MR on EE too.

TODO:
- [x] Copy docs
- [x] Make new screenshots
- [ ] Remove Custom Welcome message feature?

@rymai: I was unsure what labels to add to ping you, so I just ping you like this 😉

/cc @DouweM

See merge request !2927

Update Rails to 4.2.5.2

See https://groups.google.com/forum/#!msg/rubyonrails-security/ddY6HgqB2z4/we0RasMZIAAJ
and https://groups.google.com/forum/#!msg/rubyonrails-security/ly-IH-fxr_Q/WLoOhcMZIAAJ

See merge request !3020

See https://groups.google.com/forum/#!msg/rubyonrails-security/ddY6HgqB2z4/we0RasMZIAAJ
and https://groups.google.com/forum/#!msg/rubyonrails-security/ly-IH-fxr_Q/WLoOhcMZIAAJ

TODO detect whether request comes from China and only then show ICP (?).

We show in small font size the same info that is shown on sign_in page:

    "GitLab Nexedi Edition", "About GitLab" and "About Nexedi"

This is good to have and hereby-introduced about-footer area will be
also used in the next patch for ICP too.

XXX placement of .about-footer to be near bottom is done not very
correctly.

Like Omnibus, SlapOS version does not have init script - nothing to
check here.

This is handy for monitoring tools, which could e.g. periodically call check
tasks and instead of parsing output, rely on exit code.

The way we detect if something failed is via hooking into String#red, and if
anything was ever printed in red - that's an error.

The default was switched to HTTP in the previous patch, but let's completely
remove SSH option - we support only HTTP for git fetch/push.

Both fetch and push are possible over https, which is selected by http if
gitlab was configured to use https in external url.

This way to reduce security vectors and possible ways to interact with gitlab
we use https only without ssh at all.

= GitLab Community Edition + Nexedi patches

Created helper class to hide content in issue sidebar when collapsed

![Screen_Shot_2016-02-25_at_10.38.39](/uploads/ca49cc230edf7e71b7726e905f523092/Screen_Shot_2016-02-25_at_10.38.39.png)

Closes #13764

See merge request !2968

Fix order in Gemfile.lock

See merge request !2969

Does not create a Todo when commenting on commit or project snippet

Closes #13733

See merge request !2964

Move "I should see Crowd login form" feature to a view spec

We were doing all kinds of code gymnastics to "enable" Crowd in the
feature spec and this would sometimes cause a transient failure.

Really what it's testing is if the Crowd login form shows when Crowd's
enabled, so this is much better suited to a view spec.

See merge request !2963

Sidebar overlaps content when screen is below 1200px.

When screen is below 1200px, the sidebar overlaps.
When screen is above 1200px, the sidebar pushes content out.
z-index change to make sure hamburger stays on top.
Fixes #12717
![screensize](/uploads/9a21fa06d583a49d6ebbf1ada34c6792/screensize.gif)

![screensize-small](/uploads/7c25f46e962248a40840562a01c83f8f/screensize-small.gif)

Also sorry I couldn't get the collapse button in the screen cap. It's there.

See merge request !2620