On screen (inset) update

[Juergen Spitzmueller]

Take this as a positive feedback on the ongoing update work:
I have a minipage with lot of cruft (ert etc.) in it. In 1.3cvs, trying to 
uncollapse the minipage results in an infinite loop as soon as I change the 
width to 50%col (100%col works).
1.4cvs doesn't have any problems at all (apart from the well-known border 
offsets).
Seems like the rewrite is beginning to pay off. Good work!
Juergen.