Public projects listed in the public section will be linked to the
actual project's page. Public projects now give any user Guest
permissions to the project, allowing them to download the code, read
and create issues, and view anything else in the project's pages.

Ample access tests have been added to the project_access_spec to
verify correct permissions and behavior on public projects.
- Visitors to the site who are not logged in still cannot view the
  project's pages.
- Logged-in users visiting a public project where they are not a team
  member can create issues, but not snippets. They can view the projects
  code, issues, merge requests, etc, just as if they were a Guest member
  of the project.
- Since this is a public project, the user is also granted :download_code
  permissions, a permission normally reserved for Reporters, since they
  can clone the repo anyways and browse commits and branches locally.

The previously failing Spinach steps have been fixed with this commit.
I have also added new steps that cover the entire usage of the Wiki
system.

The new Spinach steps revealed a minor bug in the Delete page process.
The path for the "Delete this page" button was previously set to
`project_wikis_page(@project, @wiki)` when it should have been
using the singular `project_wiki_page(@project, @wiki)` path helper.

The link has been corrected and all steps are now passing.

* Module: Graph -> Network
* Class: JsonBuilder -> Graph

Refactored profile to resource. Added missing flash notice on successfull updated. Update username via ajax

- Remove compare/_head and just use commits/_head since they're identical
- Add index view; extract the form into a partial

This group is better for features that only deal with one project.

Speeds things up a bit