🚀 go-pugleaf

We've known for some time that there are occasional problems with the
way format handles text calling for half-line-up and half-line-down
motions (\u and \d) on devices which can't do such motions (the line
printer and most terminals), but Phyllis has found a new one:  the
sequence
	first\dsubscript\u\usuperscript\dsecond
produces
	firstsubscript
	              superscriptsecond

This does look kinda odd, but rest assured that it will come out RIGHT
on a device like the Multiwriter or the 1750 that CAN do half-line
motions.  This and the other related oddities are being looked into and
will be fixed some day.