adjust nginx puppet module to support fastcgi, health-check and etc.

1, add nginx reload, reload not to restart after configuration is changed.
2, change try_files's default value from undes => false.
3, add fastcgi_pass to vhost and location to support php5-fpm.
4, add nagios3 template to vhost and location.
5, add check to upstream to support health check. The patched nginx is maintained at private debian repository.
6, include /etc/nginx/sites-enabled/*.conf at /etc/nginx.conf
7, disable logging when /favicon.ico is not found at vhost.
8, add document root to vhost.