Upgrade to Rails 4.1.9

Upgrade the Rails gem to 4.1.9.  Rails behavior changed in version 4.1.2, requiring that we avoid using slashes in arguments to path helpers.  This MR changes routing to use nested resources for that reason.

TODO:

* [x] Make Spinach tests green
* [x] Make it mergeable

cc @sytse @dzaporozhets

See merge request !1494

Conflicts:
	app/views/dashboard/projects.html.haml

Update gitlab-shell to 2.5.3 in 7-8 update guide, fixes #8838

UI improvements

* filter tabs for dashboard projects page
* handle all sidebars on mobile with Aside javascript class
* remove semantic ui dependency
* fix broken sidebar for dsahboard

See merge request !1567

Move Rails 4.1.9 changes to version 7.9.

Conflicts:
	app/views/projects/commits/_commit.html.haml
	app/views/projects/issues/_issue.html.haml
	app/views/projects/issues/_issue_context.html.haml
	app/views/projects/merge_requests/_merge_request.html.haml
	app/views/projects/merge_requests/show/_context.html.haml

Change check to only swap static middleware when it's enabled.

Fixes problem with #1553.

cc @marin

See merge request !1565

Fix commit comments on first line of diff not rendering in Merge Request Discussion view.

Example can be seen near the bottom on this MR: !1533.

Before:

![Screen Shot 2015-02-20 at 10.24.34](https://dev.gitlab.org/uploads/gitlab/gitlabhq/35600b98b5/Screen_Shot_2015-02-20_at_10.24.34.png)

After: the [note](https://dev.gitlab.org/gitlab/gitlabhq/merge_requests/1533/diffs#note_36449) is actually rendered.

See merge request !1552

Redirect from /tree/master on empty repo instead of showing 404.

See https://gitlab.com/gitlab-org/gitlab-ce/issues/1114

See merge request !1559

Merge branch 'go-get-workaround-nginx' of https://github.com/mattes/gitlabhq into mattes-go-get-workaround-nginx

Conflicts:
	lib/support/nginx/gitlab
	lib/support/nginx/gitlab-ssl

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

Closes #2029, again.

See merge request !1561

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