Do the right thing with FCGI args, the hostname and the keepalive options in the...

Do the right thing with FCGI args, the hostname and the keepalive options in the scripts so that the Plack servers get them correctly.

There are still a load of options for the dev server (like writing a PID file) that we'll need to add to the plack server (or do ourselves manually?), and the entire set of options we actually pass into the application via ->run is unused by it.

I'm not sure if we are safe to change the original option passing convention or not - need to look at alternate engines and stuff..