Add triggers API

References #4264

See merge request !2286

* Use commit objects instead of IDs when generating diffs
* Use proper references when generating MR's source and target
* Update broken specs

Fixes new layout

* fix empty project page
* fix commit -> builds page missing margin

See merge request !2440

* master: (150 commits)
  fixes margin and padding
  Update mailroom/postfix documentation [ci skip]
  Fix css mess around git clone panel. Align it properly
  Fix missing padding for user/group pages
  Fix parse_gollum_tags matcher
  Update documentation on Banzai::Filter::GollumTagsFilter
  Add tests for the wiki pipeline
  Refactoring Banzai::Filter::GollumTagsFilter
  Make sure the .git is at the end on Gitlab::GithubImport::WikiFormatter
  Remove GollumTagsPipeline
  Refactoring Gitlab::GithubImport::Importer
  Remove unnecessary brackets on WIKI_SLUG_ID route constraints
  Move js function to removing accents to vendor/assets/javascripts
  Update CHANGELOG
  Use the WikiPipeline when rendering the wiki markdown content
  Add Banzai::Filter::GollumTagsFilter for parsing Gollum's tags in HTML
  Relax constraints for wiki slug
  Import GitHub wiki into GitLab
  Move Ci::Build#available_statuses to AVAILABLE_STATUSES constant in CommitStatus
  Revert changes to how the notes are paginated in the API
  ...

Conflicts:
	doc/api/README.md
	lib/api/entities.rb

fixes margin and padding

![Screen_Shot_2016-01-14_at_3.10.57_PM](/uploads/83c8b36b01439cb629c91b2dd3a85692/Screen_Shot_2016-01-14_at_3.10.57_PM.png)


See merge request !2439

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

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

Properly generate diff of orphan commits, like the first commit in a
repository

Fixes gitlab-org/gitlab_git#14

See merge request !2427

Backport two commits from EE

Backport part of https://gitlab.com/gitlab-org/gitlab-ee/merge_requests/110

See merge request !2424

Fix cross-project reference clipboard text

See https://gitlab.com/gitlab-org/gitlab-ce/merge_requests/2339

See merge request !2420

Update mailroom/postfix documentation [ci skip]

I worked with a customer to troubleshoot some strange Postfix and Mailroom issues. These doc updates aim to help other users avoid the same confusion.


See merge request !2430

Various UI fixes

* Fix missing padding for user/group pages
* Fix align of clone panel
Signed-off-by: NDmitriy Zaporozhets <dmitriy.zaporozhets@gmail.com>

See merge request !2433

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

Add builds API

References #4264

See merge request !2207

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

Add pagination headers to already paginated API resources

Following #3045, I've added pagination headers using already available Kaminari methods.

## Pagination headers in action

![Screen_Shot_2016-01-14_at_12.14.53](/uploads/88807f754dd9aafbb24da85f6bdf9521/Screen_Shot_2016-01-14_at_12.14.53.png)

---

I've also added a shared example to test paginated API resources.

A possible next step would be to paginate all the API resources that return an array.

See merge request !2426

Import GitHub wiki into GitLab

Closes #2834 

GitHub doesn’t apply any constraints to theirs wiki slug allowing chars like ,, :, *, etc, we need to remove our constraints or some wiki pages will not be available after they are imported.

Some wikis use the Gollum's tags to link its internal/external resources like: images, urls, wiki pages, etc. So, to avoid that wiki links/images displays completely broken after they were imported, we added a new `WikiPipeline`, that for now will parse only simple links, and image tags.

##### Before `WikiPipeline`:

![Screenshot_2016-01-11_20.14.48](/uploads/46fd5dbb5acfc70aa8ecca3050b675e4/Screenshot_2016-01-11_20.14.48.png)

##### After `WikiPipeline`:

![Screenshot_2016-01-11_20.15.56](/uploads/b1d94aa852f385f867a7868c358b4257/Screenshot_2016-01-11_20.15.56.png)

See merge request !2324

Unsubscribe from thread through link in email footer

Closes #3437 

![Screenshot_from_2015-12-11_15-35-06](/uploads/cfb3d8737d4757f527995411f103d0ce/Screenshot_from_2015-12-11_15-35-06.png)

![Screenshot_from_2015-12-11_15-35-56](/uploads/9b7121be7ce4b05e5995ca6d38c5bea4/Screenshot_from_2015-12-11_15-35-56.png)

See merge request !2068

Standartize buttons and fields size

Fixes #8069 and #8070

See merge request !2428