HEADs up - gcc 4.1 reversion & MSCP CD changes in current

[David Brownlee <abs%absd.org@localhost>]

gcc:

Pending someone having the time and expertise to look into the gcc 4.5
vax codegen issues I've reverted -current vax to the same gcc 4.1 used
in netbsd-6. This should at least make current usable for people in
the (probably quite long :) meantime.

MSCP CD drives:

These should now show up as racd* devices. Remember to run MAKEDEV &
update fstab. CDs without disklabels will now default to a single
iso9660 partition for the whole disk (similar to SCSI cd* devices).

sysinst:

Has been updated to take advantage of the racd* split to offer racd0a
as the default CD drive on systems with an MSCP CD drive, and cd0a on
systems with a native SCSI CD drive. (On systems with both the first
one in sysctl hw.disknames will be used).