This live CD is customized by roughly following the guidelines at:
plus a lot of other info, like ubiquity and casper source code, and
additions for making the resulting iso EFI bootable.
extract the original iso
chroot into the install (for optional manual customization)
build the new iso
boot the iso in qemu with a blank hdd, to test the install
boot the installed hdd in qemu
remove everything but the isos
time sudo sh -c "env BUILD_CONFIG=12.10 ./full-rebuild.sh"
time sudo sh -c "env BUILD_CONFIG=13.04 ./full-rebuild.sh"