[Scribus] ISO page sizes

[David Christian Berg]

Well, nobody wants to steel the picas and points and ciceros or
whatevers from you. But internally the program should use the metric
system, just because it's the better and more commonly used one. I think
it makes more sense to have exact mm than it makes to have exact pts,
because millimeters are lot easier to do calculations with. Also this
allows you to have the _exact_ page sizes for ISO pages.

David