Make Knoppix bootable from external USB CD-ROM drive

If Knoppix is booted from an external USB CD-ROM drive, it boots the kernel, but then it cannot read the filesystem from the CD, and leaves the user to a minimal shell.

It is possible to boot in "expert" mode, provided one has the modules usbcore.o, usb-uhci.o and usb-storage.o in a floppy disk. In "expert" mode, when asked if one wants to load more modules from a floppy, the three above modules should be loaded. In this case, a "SCSI" device is recognized (usb-storage makes USB devices look like SCSI ones) and Knoppix is booted from there.

So, please, include those modules in miniroot.gz. This would make booting possible for non-experts too.