[development] options in update.php?

[Peter Wolanin]

Is it currently possible to present a form and take user input when
they run update.php?

Here's the scenario I'm thinking of:

For the book module patch I posted about, it would be nice to give
users the option to convert the top-level pages in their existing book
hierarchy to the new "book" type so that they can immediatediatly ue
some of the new features.  However, to avoid altering (breaking) site
data by default, it seems best that this not be the only or the
default option.

-Peter