Support for SERVER_* to come from apache/nginx transport instead of local settings in fastcgi mode and also support for mod_fastcgi.

The first one necessary because in fastcgi mode those 3 SERVER vars were getting set from the config file and should be getting set from whatever apache/nginx is sending.

The second commit is purely to make mod_fastcgi work as mod_proxy_fcgi is not in ubuntu precise and apache either needs to be backported from saucy or compiled standalone to make it work. I tested it on both apache and nginx and it works as expected. This will make people running hhvm on precise ( and lucid as its still supported ) happy as its the LTS version :-)