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 !3019

Brings back missing "Gitlab" text on the logo

Closes #13851 

See merge request !2989

include contributions from forked projects on profile calendar

Shows contributions from forked projects in the calendar

Fixes https://gitlab.com/gitlab-org/gitlab-ce/issues/3612

See merge request !2918

Add commit message to slack script

Ass suggested by @rdavila, this adds the current commit message as of HEAD to the slack script.

See merge request !3027

Add link to triggers doc in variables section

Closes https://gitlab.com/gitlab-org/gitlab-ce/issues/13901

See merge request !3025

[ci skip]

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

Fixes padding loss after editing a diff comment

Also applies .timeago() to comment datetimes when diff page is entered directly.

Also fixes the vertical position of the comment count icon.

See merge request !3012

Revert "Merge branch 'issue_5854' into 'master'"

This reverts merge request !2992

cc @rdavila 

See merge request !3013

Fix for project paths ending in .wiki

This prevents `Git operation was rejected by pre-receive hook` when
an actual project ending with .wiki is thought to be a wiki by the
`Internal` API.

Fixes https://gitlab.com/gitlab-org/gitlab-ce/issues/13742

See merge request !2960

This reverts merge request !2992

Add commit message to JIRA's notification payload.

Closes #5854 

See merge request !2992

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

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

For !2927 

See merge request !3011

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

Removed NGProgress

In an effort to get the JS file size down, i've removed NGProgress and replaced with TurboLinks own loading indicator

Ref #13820 

![loading](/uploads/8b6ed8982e86e4b94803b56b8cd97737/loading.gif)

See merge request !3004

Changed too many changes buttons to white

Closes #13751 

![Screen_Shot_2016-02-29_at_09.18.41](/uploads/30f5d11d1a4e1785561597feeeb40f09/Screen_Shot_2016-02-29_at_09.18.41.png)

See merge request !3002

Small css cleanup for todos feature
Signed-off-by: Dmitriy Zaporozhets <dmitriy.zaporozhets@gmail.com>

Cleanup for !2817

Fixes #13816 

cc @jschatz1 @skyruler @dbalexandre 

See merge request !2996

Sanitize `data` and `vbscript` links

Closes #13625 

Closes https://dev.gitlab.org/gitlab/gitlabhq/issues/2660

See merge request !2905

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

Don't repeat labels listed on Labels tab.

Fixes #13622 

See merge request !2924

Improve discoverability for CI examples

Closes https://gitlab.com/gitlab-org/gitlab-ce/issues/13410

See merge request !3008

[ci skip]

Add "Gotchas" to development docs

Also:

- Alphabetizes the "Developer" index page
- Fixes the broken `db_dump.md` link

See merge request !2846

In an effort to get the JS file size down, i've removed NGProgress and replaced with TurboLinks own loading indicator

Ref #13820