Internal public projects

The topic of internal public projects was brought up in pull request #680 a few months ago with the outcome being the creation of teams support in issue #739. When I installed GitLab this past weekend I still wanted internally public projects rather than adding all users to a team. Thus, I took the commits from pull request #680 and modified them slightly to work with version 2.8 of GitLab. I understand that the teams issue is supposed to take care of the need for internally public projects, so this pull request is mainly just to provide an interim solution for internally public repos for those that want them. Feel free to close this request.

Patches are also available on my blog at: http://shanetully.com/2012/08/gitlab-internally-public-projects/