Merge pull request #56 from rfairburn/master

Fix support for os_family RedHat
Merge pull request #57 from rfairburn/master

Use nginx_map.default_group for group in all places
Allow selection of repo_version
Update pillar.example
Merge pull request #58 from OneID/feature/repo-version

Allow ppa install using development/mainline etc
Force overwrite of /etc/init.d/nginx
Merge pull request #59 from OneID/feature/upstart-symlink-checking

Force overwrite of /etc/init.d/nginx