Fix note attachments XSS and access control

Replaces the reverted #1528, as proposed in https://gitlab.com/gitlab-org/omnibus-gitlab/issues/434, as discussed with @dzaporozhets and as summarized in #2032.

@marin Could you take a look at the nginx config and apply it to Omnibus once this gets merged?

See merge request !1553

Added gitorious.org importer

Heavily inspired by GitHub and GitLab importers.

See merge request !343

Improve web hooks

* add git_http_url and git_ssh_url to project web hook
* add visibility_level to project web hook
* add documentation about project visibility_level in API

Fixes #2018, #2030

cc @sytse

See merge request !1560

* add git_http_url and git_ssh_url to project web hook
* add visibility_level to project web hook
* add documentation about project visibility_level in API

Base new MR title on commit title if there's only one.

Closes #2029.

See merge request !1558

Fix commits calendar vertical days.

Fixes #2031.

Before:

![Screen Shot 2015-02-20 at 14.36.31](https://dev.gitlab.org/uploads/gitlab/gitlabhq/08d322797b/Screen_Shot_2015-02-20_at_14.36.31.png)

After:

![Screen Shot 2015-02-20 at 14.35.54](https://dev.gitlab.org/uploads/gitlab/gitlabhq/0cfbabad26/Screen_Shot_2015-02-20_at_14.35.54.png)

See merge request !1555

Update CHANGELOG

Add myself to the changelog for the Asana service #8580

UI improvements

* lighter color for comments count
* better UI for issue assigee.milestone block

See merge request !1551

* lighter color for comments count
* better UI for issue assigee.milestone block

Ui improvements

* improve UI for commits, issues and merge requests lists
* refactor commit css

See merge request !1550

Ui improvements

* update bootstrap
* move milestones and labels to the left
* make open/closed/all filter as tab
* make issues page more compact

For  #1871

See merge request !1549