Fix for printouts without margins

[Goffioul Michael]

> > 2) the GUI of the margin property page does not reflect the change
> >    of default values
> > I thought about adapting the default margin values with the fullpage
> > flag (false -> use Qt's default, true -> use physical values), but
> > this would require additional work in the margin property 
> page as the
> > settings there are system-widely saved (or not) if they differ from
> > default values, while the actual default values might 
> change from one app
> > to the other.
> 
> The property page only shows up if using setFullPage(false). 

Indeed, I forgot that...

> > The best is probably to use as default the max between the 
> physical margin
> > and some reasonable standard margin. But this has to be 
> done (at least)
> > in kprinter.cpp and in kpmarginpage.cpp.
> Thanks for the hint. Done in the attached patch.
> 
> The margins property page now shows the margins that are indeed going
> to be used by default.

Patch looks OK to me. One further step would be to add minimum
values to MarginWidget and not let the user specify smaller
margins. Conceptually, this means:

	m_margin->setDefaultMargins(QMAX(Qt,driver));
	m_margin->setMinimumMargins(driver);

I don't have time/resource to do it myself, so if anbody's interested...

Michael.