Consider generating dynamic d-i preseed file #81
Description
Currently, the debian-installer preseed file is static is common to all servers and VM. This sucks when servers require different settings. The current workaround is to set parameters on debian-installer kernel command line with help of the bootmenu CGI. But the list quickly becomes relatively long with simple parameters. And this may not work if, for example, someone wants to set different partition scheme on different servers.