Onserver scripts hard-code deploy directory

[ezyang]

All of the onserver scripts for autoinstallers hardcode the deploy directory:

use strict;
use lib "/mit/scripts/deploy/bin";
use onserver;

As a result, scriptsdev=dev doesn't result in deploydev onserver.pm being used.

Fix is somewhat unclear. Can we make Perl read out of the directory the script lives in?

[ezyang]

Fixes issue