No more TOS

[ekl@sdf.lonestar.org]

It would seem that the general trend is to get rid of the threads holding
MiNT onto TOS.  No more BIOSFS - separate XDD drivers, and no more TOS
code for disk accesses - a SCSI XDD driver instead (has anyone thought
about floppy?  That isn't SCSI and MiNT doesn't seem to always realize
a disk change as much as TOS, as long as we rewrite everything else, you
might as well rewrite the Floppy drivers too - some code to have the step
rate changed automatically for 1.44MB and 720K disks would be nice as
the stupid AJAX doesn't do this change (although new TOSs might). 

I also like the idea of having the buffering done by the device driver 
and not the file system, however, the file system can be more efficient
by buffering itself - keeping important sectors in memory, such as TOSFS
should buffer the FAT tables itself and allow the SCSI driver to buffer
DATA access - make sense?

Some have said that we need to keep some drivers part of the kernel in case
of some error.  Obviously MiNT will need to communicate to the user when
the XDD files are not found, like if the console.xdd is missing.  This is
a serious error in which case MiNT should unhook itself from the system
and call the BIOS to print an appropriate message and then boot the ROM
TOS.  If MiNT were put in ROM, THEN we'd need the console and some other
standard drivers as part of the kernel - otherwise its easier to keep them
separate.