this pull request enables xorg in the build

Use "xinit" to start xorg. I renamed all puppy scripts that replace common utilities (e.g. df, mount, umount, etc) with a -puppy suffix (eg. to df-puppy, mount-puppy, etc). This got renamed back to the actual names by pinstall.sh; and pinstall.sh will rename the original binaries to whatever-FULL.

pinstall.sh also contains some changes to make sure that hotplugged xorg will work - these changes should go into rootfs-skeleton but I haven't done it yet. There are also some (probably) ubuntu/debian specific fixes in pinstall.sh that should go to its own extra-packages; but I haven't split it yet.

deb-build is updated so that it can build *without having to install dpkg* first on the system.