update component lists: scsipi is independent of umass now

* support cd devices (@scsibus & @atapibus, per libumass)
* support cd9660
* add "probe" keyword, which just prints the dmesg in verbose form

rumpusbhc is now ugenhc

WARNS

Try ffs is msdosfs mount fails -- I happened to have one USB stick
where the file system is ffs.

Add an example program which shows how to mount and read files from
an msdos file system which is located on a usb stick. What makes
this special is that the USB driver stack (and the file system
driver, of course) is run in rump instead of in the host kernel.

Check open return value and close fd when we're done.

Use DIOCTUR to test if a newly configured CD drive is ready instead
of playing a random waiting game.

Pause after probe here too, so that you can amuse yourself by
unplugging and replugging devices and looking at the detach/attach
feedback messages.

* support cd devices (@scsibus & @atapibus, per libumass)
* support cd9660
* add "probe" keyword, which just prints the dmesg in verbose form

Try ffs is msdosfs mount fails -- I happened to have one USB stick
where the file system is ffs.

Add an example program which shows how to mount and read files from
an msdos file system which is located on a usb stick. What makes
this special is that the USB driver stack (and the file system
driver, of course) is run in rump instead of in the host kernel.