I totally misunderstood the even/odd spec.  Add some docs, remove my 'left+' hack, and orthogonalize left/right versus even/odd so you can specify them independently.

pdf has very good page breaks now.
would be a good copy for fall 2009.

also thanks to greg price.

thanks to greg price.

New formatting scripts.

The use/defs extraction in runoff still needs some work
for xv6 code style.