the pipeline function is a little bit from a long time ago.
it doesn't change functionality.

the but is that with a proportional font, man 2 draw
ends up with terrible tabs in it.  compare:
hget http://www.quanstro.net/plan9/nroff/good.png | page
hget http://www.quanstro.net/plan9/nroff/bad.png | page

col is doing fancy tab subsitution and just doesn't know
enough to do it right.