sysinst: tsubai-san says that macppc doesn't suffer from install-related
pcmcia interrupt problems. removed those for macppc
upgrade: add conditional for macppc and sparc (don't need to boot
from floppy)
- use .Ic, .Pa, .Key, .Ul, .Tn, .Sq, .Dq as appropriate
- use .Dl instead of .(disp when formatting changes are required (the latter
doesn't cope too well when font change macros are used)
- wrap .Dl blocks with .Pp
- consistently use `file system' instead of `filesystem'
- migrate macppc to common/xfer