Added NGXCB and make use of it within nginx.sh

NGXCB (Nginx Create Block) makes it easy to quickly create and optionally enable it right away. Type in `sudo ngxcb -h` for more info.
Add HHVM support for Nginx
Some minor cleanup in ngxen and ngxdis
Removed hhvm/install_fastcgi.sh execution from nginx.sh
Merge branch 'master' into develop
Merge branch 'master' into develop
Merge pull request #318 from Ilyes512/nginx-create-block

Nginx create block
slight cleanup
apache takes care of hhvm or php proxypass
DRYing up github urls in the vagrantfile
Add all helper files and use the github_url variable